Sunday, October 18, 2020

Sulfate-Free Shampoos: Part 1

Hi All!

This series is brought to you by virtue of my developing a sensitivity to the shampoo I'd used for about 9 years. I "DIY" my shampoo, so let's learn together. This isn't so much a lesson in "the science of detergents." This is going to be related to the way they work in a product and how that translates into your experience. "Surfactant" is a technical term for detergent and I tend to use them interchangeably. Here, I'll call them detergents.

Sulfate-free shampoos have some advantages and disadvantages. There are many characteristics of ingredients that contribute to the experience of using a product, and our perception of the product. This goes beyond the simple question of "whether sulfates are harsh or not."

The first thing I want to mention is concentration and foam. They are very much related. For every positive, there is a negative. That's life, right!? 😀

In order to have a nice foam, a product that lathers up right away, bubble size isn't too large nor too small and dense, one often needs a higher concentration of the sulfate-free detergents than traditional sulfate detergents (Sodium lauryl sulfate, Sodium laureth sulfate, Ammonium lauryl sulfate, Sodium laureth sulfate).

The only sulfate-free detergent that lathers well for me alone at low(ish) concentrations are the Glucosides (Decyl glucoside, Lauryl glucoside). And while the glucoside-detergent molecules are too large to penetrate hair and skin and therefore mild to skin, they can still lead to dryness because they de-grease (form micelles) at relative low concentrations - thus the foam!.  That makes it a mild, but still potentially oil-stripping detergent. Oh, the irony! You'll often see this detergent combined with others for it's foam-boosting power, and for added mildness to skin. (Seriously, don't avoid this ingredient, it was my favorite for my picky skin for years. It's an excellent ingredient for mild shampoos).

Other sulfate-free detergents foam less on their own, but help thicken a product or add mildness to skin (such as Cocamidopropyl betaine, Sodium sulfosuccinate, Sodium cocoyl isethionate).

Product formulators need to do more detergent-combining to find a product that will achieve a nice sensory experience - because nobody likes wimpy foam that disappears immediately. But we also want it to rinse out quickly and easily. With sulfate detergents, detergent-combining tends to be more straight-forward. Add 1 detergent for mildness, maybe another for foaming and you're done.

If you're creating a "boutique" shampoo for a specific audience, you have more flexibility in the end product. So you can use the (more expensive) sulfate-free detergents because we assume you're going to charge more, and also to manage people's expectations as part of the "brand." But if you're going for a broader market, you need to meet a wide variety of expectations. That probably means more detergent.

Detergent concentration has a lot to do with irritancy and oil-removal. A higher concentration of mild detergents can sometimes be as irritating or as oil-stripping as a lesser concentration of sulfate detergents. A lot depends on other ingredients in the formula.

Take-home message: Combining detergents is the key to great shampoos! 

Up next: More topics in sulfate-free shampoo:

Thickening, conditioning, skin irritation, hard water interactions, mildness-creation for hair and skin, that tangly squeaky-clean feeling.

Saturday, September 5, 2020

Oils - Some Thoughts for Troubleshooting

Hi all! I wanted to pop in and highlight some issues with oils. Oils can be a challenge - lots of us feel like maybe we should either be using them (alone or in products) or at least be able to tell whether oils are causing problems for our hair (alone or in products).


Because “oil causing problems” can look like dryness, frizz, stiffness, dullness, or even hair-breakage, we need lots of different ways of looking at the ways oils behave in their environment. By that I mean - in storage as well as in your hair.

1) Oils are at the mercy of nature, they can break down. Oils are fats - and fats can go “bad.” Under even ideal conditions, oil molecules can break down to smaller parts. Every oil is made of chains of smaller fatty acids. They can be arranged quite differently depending on the oil, and have very different properties as a result. Breaking down an oil is like smashing a Lego creation. Yes - it’s still made of Lego pieces. But the whole creation loses integrity when broken down into its constituent parts. A broken-down oil may not behave in the same way as you expect from a fresh oil.

- When exposed to air and sunlight, or air and heat, some oils are highly susceptible to oxidation, the process of oxygen attacking some of the chemical bonds in the oils. This happens if oils are stored improperly or for too long. Unsaturated or less-saturated fats are highly susceptible to oxidation; that includes most plant oils that are liquid at room temperature, such as olive and sunflower, flaxseed, hemp seed oils.

That breaking down process is one you’ve observed when you use an oil preservative on wood or leather. Such oil-based preservative products are applied as liquids and soak in quickly. As they dry they may become tacky (sticky and stiff) and darkened in the sun and wind. The oil’s chemical structure changes through oxidation.

Something like this might also occur in your hair - it's more likely to have occurred during storage - but that last bit of heat and/or light might be the "final straw.". Oils in hair are exposed to oxygen and sunlight - and heat if you use a hair dryer or heat styling tools. If you notice that some oils seem to change in performance within several hours of application - oxidation may be part of the cause.

A product containing 0.5% olive oil will behave differently than applying 100% olive oil to your hair. Keep that in mind as well!

- The other process occurs in the presence of water and breaks triglycerides (which are a common form of fatty acid in plants) into the fatty acids and glycerol that triglycerides are made from. In well-formulated, water-based hair products this probably won’t be an issue, but un-formulated oils (plant oils straight from the bottle) applied directly to wet hair might introduce this possibility if hair takes a long time to dry, or if you had mixed oil into a water-based product or in a water bottle with other ingredients. If you’ve noticed that oils work differently when applied to wet vs. dry hair, this might be one reason. It's more likely if you make your own products with oil like flax seed gel and notice the product’s performance changing after a while - this also might be what is happening. Store homemade gels in the freezer for good preservation. A product with a formula that does not adequately stabilize the oils may degrade or destabilize over time. That could cause odor change, color change, separation, change in product texture and performance.

Storage considerations:

If you use oils, store them in a dark, cool place or in opaque bottles. Keep air out by capping them quickly after opening, storing in a not-too-large jar. An airless pump bottle would be ideal for storing oils - especially the pricier ones - that you use regularly and want to keep at room temperature, or that go bad quickly. Keep moisture out of oils and butters too. Don’t put wet fingers into a bottle or jar of oil. Don’t store oils or butters in the shower. Less obvious (but still a problem) is condensation inside a bottle and this is more related to having your products exposed to temperature extremes, which it’s best to avoid. If you open an oil product or an oil-based product and there is moisture under the lid or cap - dry it off thoroughly before replacing the cap.

Oils less susceptible to breaking down in light, heat, and moisture: Jojoba, coconut, palm kernel, palm oil, morgina oil, sea buckthorn oil, peanut oil, butters (shea, cocoa, etc.). Squalane and Capric/Caprylic Triglycerides are cosmetic ingredients which also tend to be very shelf-stable and may have better stability. Butters like shea and cocoa and (sometimes) solid-at-room-temperature oils like coconut and babbasu are higher in saturated fats, which may resist breaking down, but they also do contain unsaturated fats, so they are not immune. 

No oil will be optimally stable if it is stored in high heat, in bright light (or sunlight), or in a poorly sealed container.

Ingredients in products which stabilize oils: Vitamin E, butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), tetrahexyldecyl ascorbate, tertiary butylhydroquinone (TBHQ), ethylenediaminetetraacetic acid (EDTA), 6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline (Ethoxyquin), Propyl gallate (PG).

2) Emulsification of oils: When oils are emulsified in a product, the oil and water in the product have been treated so that they do not separate. This process is done with 1) emulsifiers (that’s a class of ingredients), 2) heat (usually) and 3) high speed mixing. Oils that are emulsified in a product may behave differently in hair than oils that are used straight from the bottle of oil. This is both a cosmetic and a texture difference! Compare this to the difference between oil-in-water salad dressing compared to creamy (emulsified) salad dressing. The difference in the way they pour, the way they cling to different vegetables or fruits, or to wet and dry surfaces. Think of how those 2 kinds of salad dressings dry on a salad bowl or a tablecloth or napkin. Sometimes the problem with oils is that we’re trying to use them alone when our hair might get along better with them when emulsified into a product.

It is so easy to over-use oils because a little oil can often treat a large surface area adequately. When they are pre-measured in a product, it’s harder to accidentally use too much. Emulsification also assures that the oil is distributed evenly - in the product and on your hair.

3) Some oils penetrate into the hair over time, some do not. More information can be found here. If you need softness or porosity-management from oils - the more-penetrating oils may be a good choice. If you need lubrication, a non-penetrating (or less-penetrating) oil may be right for your hair. Or a blend of those. Oils are complex ingredients, using the right one to its best effect can take trial and error and creativity.

4) Oils are a natural product from plants: Plants are living things growing outdoors. Different soils, different seasons, different varieties of plants can all produce slightly different products. Growers do their best to produce a reliable product - their income depends on it - but they can’t control everything. It’s normal for plant oils to have slight variation.

5) Hair is an infinitely variable medium: Your hair is a product of your genetics, your nutritional status, your scalp health, your climate, your water chemistry, your styling products and techniques, and any treatments you have used (including coloring or lightening or curl-changing). Hair is as unique as skin. As unique as personalities. There is science behind formulating hair-care products, but it’s not always certain who an oil (or a product) will work well for. Personal preferences are part of that equation. There are no absolute rules for right and wrong with oils and hair - there is only what works. Look for consistency from use to use. If you are getting oil-use and oil-choice right, it will perform in a predictable way each time you use it. That does not mean you need to use oil or an oil-right product every time you wash or style your hair unless you prefer to do so. Sometimes hair does best with variety. If we do the same thing every time we wash or style our hair - we miss opportunities to be creative or discover something new - or identify a problem.

6) Over-application: Self-explanatory, right? Think of oils as a cosmetic active ingredient - they are super-concentrated actives when undiluted. Even just a tiny bit more than you need can make hair behave strangely. Our scalps, when they are healthy, don't produce a lot of oil, and they produce a mixture of oils that are solid and liquid at body temperature. When we put more oil on our hair than nature intended, it's more likely that strange things will be going on with your hair. You've probably noticed this if your scalp has become extra-oily for any reason. For some people regarding oil use, smaller amounts of oil pack the best treatment-punch because you won't need to use lots of cleanser to remove the excess and you won't have weird side effects.

The take-home message:

For people who have a lot of difficulty with oils causing dryness or frizz, tangling or dullness, part of the problem may be oils’ stability in the presence of air, light and water - and part of your solution might be to look for more-stable oils alone or else limit oil-use to oils in products. The oil in products will usually be stabilized by other ingredients in the product.

If an oil breaks down in the bottle or on your hair, it may no longer have the behavior of the original product. So the result might not be desirable. We do not control how an oil is stored before it gets to us! You can do everything right and still have trouble with oils.

Oils are not purified ingredients, they are like complete products in themselves with not only fatty acids, but a number of other chemicals that plants employ for a variety of purposes. What works for plants doesn't always work for hair!

Why use them if they're so tricky? Because when you get oil-use right, there is nothing that softens or smooths or creates flexibility like oils.

If you’ve read this far - comments: I will try to allow comments to be posted at some point in the future. That process is going to take some time that I cannot commit to just yet.

Monday, December 24, 2018

Product pH List

This is a short-looking list but read carefully, for some brands or some lines within a brand, the pH range is for multiple products. Some brands are not forthcoming with their pH range, either by direct request or looking through safety data sheets.

pH is given in a range because it may vary from batch to batch or product to product, though the pH needs to be in a specific range in most cases in order for preservatives to be effective and the product to be stable on the shelf.

Hair is at its least vulnerable between about pH 4.5 and 6.5. Outside that range, it is more vulnerable to damage. Lower pH products don't necessarily force cuticles to "close" - for some people the opposite can happen - hair-swelling in very-low pH can cause cuticles to pop up. It's likely safe to keep products in this range if you have delicate, breakage-prone or damaged hair.

ProductpH Range
Alterna Bamboo Smooth anti-frizz shampoo6-6.5
Alterna Bamboo Smooth anti-frizz conditioner3 - 4.5
Aussie Instant Freeze Gel7.5-8.5
Aussie Mega Moist Conditioner: 5.3-6.7
Aussie Mega Moist Shampoo5.3-6.7
Castile soap (liquid, un-diluted, such as Dr. Bronners)8.9-10
Design Essentials Honey Crème Moisture Retention Super Detangling Conditioning Shampoo5.8-6.6
Clay, bentonite mixed with distilled water~8
Clay, rhassoul, mixed with distilled water6.5-7.5
Design Essentials Kukui & Coconut Hydrating Conditioner5.8-6.6
Head and Shoulders Dandruff Shampoos4 to 6
Herbal Essences Conditioner: Hello Hydration3.5 to 6.5
Herbal Essences Conditioner: Long Term Relationship3.5 to 6.5
Herbal Essences Mousses5.5 - 6.5
Herbal Essences Set Me Up Gel7.5-8.5
Homemade Flax Seed Gel (made with distilled water)5.3
LA Looks Mega Mega Hold Styling Gel5 to 6
LA Looks Sport 5 to 6
Lemon juice (undiluted) ~2
Long Hair Don't Care products5.5 to 6.5
Shea Moisture Brand Products (this is the range they provide for their products)5 to 6.8
Soultanicals (All products except Master Hair Cleanse)5.5 to 6.5
Suave Conditioners - all Variations5.2
Tresemme Conditioners (All varieties)5
V05 Extra Body4 to 5
Vinegar (undiluted)2-3

Saturday, December 22, 2018

Blog Comments

Hello Everyone - just popping in to say I'm working on the Comments section.

I tend to get about 2-3 "spam" comments per actual comment, so I "moderate" comments before they appear or you'd have to read through a page full of spam-advertising for hair transplant clinic and the like. Recently I have not had time to do any of this, and to make matters more annoying, the "spam load" seems to have increased significantly.

Please bear with me while I sort this out.

Sunday, August 12, 2018

Flax Seed Gel Diagnostics: The Video!

There are plenty of "how to make flaxseed gel" videos on YouTube, right? I made this video to show you how to tell whether you're going to get a thin, easily strainable result or a thick, difficult-to-strain result. Because flax seeds are a natural product and how they behave when heated can vary based on seed variety and growing conditions, storage time and conditions, your water, how fast you get to the stove when you hear the seeds boiling, how low you turn down the heat when they boil - you need more cues than just timing.

Thinner flax seed gel: Boil the water and seeds about 5-8 minutes. The gel will thicken over the heat a little. Gel will hang in thin threads from your stirring utensil (see the video). The gel will strain quickly and easily.
This gel will provide some support for your hair, shine, all the good things flax seed gel can do. This thinner gel is good for thin or fine hair, hair that is easily weighed down or tends to be low porosity.

Thicker flax seed gel: Boil seeds 10-15 minutes. Some people boil them longer than that. The gel with be thick over heat, you'll get thicker strings of gel hanging from your stirring utensil. It will not run readily through a strainer, it will require some pressure. I usually mash with a spoon, some people strain through the cut-off foot of nylon stockings. NOTE: having your hands contact the gel while straining through nylon stockings will contaminate the gel! You'll need to re-boil it to kill bacteria if you want a long shelf-life in the refrigerator.
This gel will provide extra support and thickness, it might be too softening or heavy for thin or fine hair or hair that tends to go limp easily or is low porosity. Possibly great for thick or coarse hair.

Overnight-soak flax gel will tend towards the thicker side upon boiling. The longer the seeds are in water, the more mucilage/polysaccharides (gel!) can be extracted, whether that is an overnight soak, a longer boil, or leaving the seeds in the hot water after boiling.

Whether or not more mucilage/polysaccharides (gel!) is better depends on your hair and your personal preference.

Links to flax gel recipes on this blog:
Basic flax seed gel recipes with ideas for add-ins.
Super-Smooth Flax Curl Cream
Flaxseed Curling Cream (uses commercial strong-hold gel)
Flaxseed/Aloe Gel with Protein (scroll down a bit)

Watch the video to see demos - and what seem like awkwardly long close-ups of my strainer and Pyrex measuring cup.

Sunday, August 5, 2018

Conditioning Technique: Squish to Condish, How it Works

First of all - this is not my technique. It was named by Melissa Stites, hairstylist and owner of There Once Was A Curl salon in Southgate, Michigan. Squish to Condish is a conditioner-rinsing method for which you can find Ms. Stites text here on her blog - which she has generously shared and it is helpful to so many people. This technique is meant to leave some conditioner in the hair and achieve excellent hydration and lubrication. I often recommend this technique, so I've had to think quite a lot about why it works so well. You can find videos on YouTube demonstrating the technique.

I use un-glamorous words like hydration and lubrication for hair. Because they seem most literal and accurate to me.

When hair is hydrated - meaning it contains a certain percentage of water - it is flexible. Dehydrated hair becomes inflexible, which is part of what we mean when we say hair feels dry or, "like straw." Flexible hair is more pliable. It can be shaped when wet. It has some weight or heft when dry. It will group more readily with neighboring hairs into waves or curls during styling. If your hair is straight - hydrated hair is less likely to spread out at the ends (like the end of a broom) if it is well-hydrated.

When hair is lubricated, hairs can settle in snugly next to neighboring hairs. Lubrication reduces friction - and friction creates frizz.

Squish to Condish: This method enhances 4 important elements to conditioner-use.
  1. Adding water to conditioner once in the hair to take advantage of conditioner's action as a "wetting agent." Wetting agents like surfactants (and conditioners contain cationic surfactants) help a conditioner overcome hair's resistance to water absorption. This is a little counter-intuitive because conditioners also help hair repel water once adsorbed to the hair. But don't over-think it - instead try it yourself. You'll find that if your hair tends to repel water and be slow to wet, applying conditioner to it first helps it become wet more quickly. Shampoos are even more effective wetting agents than conditioners.
  2. The physical manipulation used - scrunching, gliding, pressing hairs together, gentle squeezing, finger-combing, helps saturate hair evenly. Like kneading bread just enough - there will be no little bits of dry flour here and bits of wetter dough there after you've done this. The hair is more evenly saturated with water, and evenly coated with more-fluid conditioner.
  3. Better contact with all hair surfaces means conditioner can bond to more bonding-sites on the hair, and with it, water for more thorough saturation.
  4. More of the hair-penetrating ingredients can find their way into the hair because of better coverage, and more thorough saturation. That includes ingredients like Glycerin, Panthenol, Amino acids, Cetrimonium chloride (or bromide).
This is not a technique for smoothing down cuticles. As far as cuticles are involved - between cuticle edges is where water can seep past, and with it, some of the humectants and conditioning ingredients and oils in conditioners. Conditioners also bond to cuticles and their edges. But conditioner and Squish to Condish doesn't change the cuticle-condition, nor the cuticle position. This technique alters elements of flexibility, hydration and lubrication to change the behavior of the hair strands.

I admit it took me a long time to get to writing this post because I was having trouble with the visual aids. I wanted to use real hair, but imaging hair with conditioner on it is difficult. I decided on silver hair for its translucence, and I added blue dye to the conditioner for visibility. The dark lines in the center are medullas. The conditioner appears as some blobs or irregularities on the sides of the hair. In the end, I had to "enhance" the final images a little to show you what seems so helpful about this method to me. 

Above: Hair with conditioner smoothed over the surface. The conditioner is blue. This seemed like good coverage to the naked eye and to the fingers. The blue dye worked fairly well If you *click to enlarge* the photo, you can see some blurry areas of non-blue conditioner which did not retain the dye. Conditioner coverage is not very continuous when just smoothed over the hair!

Close-up of hair with conditioner smoothed over the surface. Coverage is patchy.

Now the Squish to Condish hair. 

Hair using Squish To Condish - water added to conditioner on the hair, squeezed together, but has not has the excess water removed - a little more water/conditioner removal would be the next step. Blue coloring is spread more evenly over more of the hair, meaning more conditioner has contact with the hair, and the hair is better-hydrated from having "kneaded" the water and conditioner into the hair.

Squish to Condish hair close-up - blue-colored conditioner covers most of the hair surface.

Keep in mind - this is a dramatization to help you visualize and understand how this technique works. I did work with real hair and real conditioner - it's a conditioner with a little protein and oil, so this is very close to what happens in your hair.

By "kneading" the water and conditioner into your hair, you create a more-hydrated, better-lubricated, more malleable result. Just like kneading bread or mixing muffin or brownie batter to assure every bit of dough/batter is properly prepared.
Even if you need to rinse out your conditioner after conditioning due to sensitive skin, or hair that tends to become limp or develop an oily or coated appearance, this technique still provides much better conditioning that combing conditioner through your hair and hoping for the best.

Sunday, May 27, 2018

My Problem-Scalp Line-Up

Greetings blog-readers! The blog has been quiet because while I have ideas for blog posts, they generally take more hours to carry out than I have to write them. This is not intended as medical advice and does not replace a consultation with a doctor. Use any and all treatments at your own discretion - or ask your doctor or pharmacist. Nor does it replace buying half a dozen dandruff shampoos and handing them off to a family member or friend when they don't work for you. Alas. I buy these products myself - this is not a sponsored post. Everything you see here should cost less than $25.

I have an entire page dedicated to itchy, flaky, bumpy scalp products because so many of us encounter those problems from time to time, or on a more or less constant basis.

What kind of scalp problem do I have? My skin falls into the "atopic dermatitis/eczema" category. Also "seborrheic dermatitis." I don't see those things as separate entities, there is overlap, even though eczema usually means dry skin and seborrheic dermatitis usually means oily skin. Atopic dermatitis means you have allergies, and part of your allergic reaction is your skin barrier breaks down when your skin is bombarded by allergens - things like mold spores, pollen, pet dander. But because allergies have an inflammatory component, some people's skin "learns" that inflammation reaction and will also become inflamed - dry, red, painful, peeling or flaking, raw - from exposure to wind or cold or heat or pressure (hat-wearing or headbands).

The "seborrheic dermatitis" component applies because scalps (and eyebrows, noses, cheeks, chins) can sometimes be more-oily. And sometimes the flaking and peeling of skin is a more-visible symptom in these areas. And oiliness - greasy hair. But for some people, that "oiliness" actually looks like thick, waxy, yellow flakes. Or it may feel like a waxy/powdery residue or "scalp build-up" that accumulates under your fingernails if you scratch your skin, or leaves that residue on your fingers if you rub it. Some people get "scalp acne" or bumps or cysts.

What do I use? The right treatment varies a lot from person to person. I have skin that reacts badly to a lot of products, and I have tried many dandruff treatments with very few "hits." This is what works for me, when it works and why it works.

Scalp massage: Before washing, or between washes if you go several days between washes. Nothing fancy, massage the scalp gently with the finger-pads (not the nails - if you have a very sensitive scalp, that can leave you with skin damage). Then I stroke my fingers over and through my hair - which spreads any oils over the hair and can help hair feel more-hydrated and flexible after washing.

*For people who have a waxy, thick build-up, a shampoo brush can do a great job loosening that up. Using very warm water helps to soften waxy oils (or a warm towel wrapped around the head), by bringing them closer to their melting point so they're easier to remove - but if heat makes your skin worse, just use water as warm as you can tolerate.

DHS Sal shampoo: For dry-weather peeling/flaking and humid-weather itching and bumpiness. This product contains Salicylic acid to act as an exfoliant to remove skin cells which need shedding. Those of us with problem scalps tend to need help with exfoliation because our skin is not functioning like healthy skin, and skin cells which should be shedding freely tend to stick together instead. That can provide a moist little environment for yeasts and bacteria - the ones that normally live on our scalps without causing a problem - to grow more than usual -causing itch and inflammation. FYI: Yeasts are a kind of fungus. Good exfoliation can help keep your microbial community in check.

I use this 1-2 times per week when my scalp is flaring up. I wash my hair frequently to remove allergens. This shampoo is fragrance-free and contains no conditioners - which are a problem for my skin. My hair is short, but if it were long, dry, highlighted, relaxed, dyed, heat-styled or damaged, I would want to condition it before washing as well as after to protect the hair from drying out. An oil pre-wash treatment would also protect hair from drying effects of shampoos such as this. This shampoo is meant to de-grease hair and scalp, but not all itchy and flaky scalps are especially greasy. Mine isn't. I usually wash after this with my favorite mild shampoo to make sure there will be nothing left behind to cause itch.

I can't buy this product locally, so I order it directly from Person and Covey - their shipping is quick and I'm certain to receive a product which has not been sitting in a warehouse for too long. As I write this, it costs $8.60 for a 4 oz. bottle. That skimpy little bottle lasts a long while unless more than one person is using it.

Hydrocortisone cream: For applying to itchy, peeling, red (inflamed) or flaky areas. Some people get flaking and peeling all over. My scalp will flake or peel in patches (usually) with itching. So I can spot-treat with hydrocortisone cream, which reduces inflammation and itching quickly.
Cortizone-10 is my favorite, but I'll buy a generic if the ingredients are the same. In other countries, this anti-itch medication will have different brands, but the active ingredient is Hydrocortisone 1%.

That which needs extra medicine: When hydrocortisone cream fails, in summer when it is humid, when I've been sweating, if there has been a dramatic weather change, I've been wearing a hat, etc., the yeasts on a sensitive scalp (and sometimes bacteria too) can get a little out of control and that means extra itching, inflammation - usually slightly different symptoms than during our more-dry, colder winters. Sometimes it seems to turn on an allergy response, if you're not outright allergic to molds/yeasts to begin with. In which case, your eyes might itch or get watery, you might feel tired or foggy-headed and your mind will drift to washing your scalp and it's really, really hard not to scratch. This is the muscle for really bad skin days.

Tinactin antifungal: This is what I use to spot-treat itchy areas when topical Hydrocortisone does not work. Designed for athlete's foot, a fungal skin disease - this cream works so quickly when I need it on my feet, I decided to try it in my itchy pool-ears and eyebrows and after a few applications, things are usually back to normal. Sometimes I need to use this in addition to hydrocortisone cream on an itchy/peeling spot. One could use any brand or athlete's foot treatment you like, this is the one that gets along with my skin and works very fast. I use it to spot-treat my scalp sometimes. It's a cream, and it comes in a small-ish tube, so obviously I'm not going to put this all over my scalp. The active ingredient is Tolnaftate.

Zinc, Ketoconazole and antifungal shampoo/conditioner or treatments: I like DHS zinc shampoo, but the fragrance is strong. If the itch of an itchy scalp is more than I can spot-treat, and Salicylic acid shampoo isn't getting the job done, it's time to try something anti-microbial.
Pyrithione zinc shampoos like this tend to work for lots of people by reducing yeasts on the scalp. There are Pyrithione zinc, Ketoconazole shampoos and Piroctone olamine shampoos and treatments in a list on this page. Those are also anti-yeast.
I use these "as needed" because I've been dealing with this for years and I know (mostly) how my scalp will respond - usually a few uses is enough for me if I'm using other treatments at the same time - which I do. Usually one needs to use a medicated shampoo for about 2 weeks, and then less often for maintenance after your scalp has cleared.

Antihistamines: For those of us with seasonal allergies, taking antihistamines regularly when you need them, assuming it's safe for you to take them, can help minimize the intensity of skin reactions.

There you have it - one person's strategy for dry-weather scalp problems, humid-weather scalp problems, and things in between.