Scalp: your complete guide
Most people are so focused on the appearance of their hair that they forget that healthy hair begins with a healthy scalp. When patients come in concerned about hair loss or hair disorders, the first thing I do is closely examine the scalp with a dermatoscope. I look for evidence of redness or erythema, scaling or flakiness, how ‘boggy’ or swollen the scalp can feel, pustules, ingrown hairs, scar tissue, and evidence of clear follicular openings where hair can grow through. A healthy scalp will be soft to the touch but not tender and not too boggy, have no evidence of redness or erythema, no scaling or flaking, one to just a few hairs growing through one follicular opening, and no evidence of keloids or growths and rashes. It is important to look for each of these things. For example, the ‘doll’s hair’ look to some scalps with tufts of hair growing through one hair follicle can be evidence of chronic inflammation and scar tissue that has blocked healthy hair growth. The most common reasons for scalp itching and flaking tend to be seborrheic dermatitis, psoriasis, and irritant or allergic contact dermatitis. Seborrheic dermatitis very common from infants through adults is thought to be related to an inflammatory response we have to the presence of a yeast on our scalps called Malassezia. It results in dry, flaky, itchy skin on our scalp. Sweating, stress, and temperature changes are common triggers for this condition. Psoriasis is a chronic immune mediated or autoimmune skin condition. Psoriasis is common! It is estimated to affect about 2-3 % of the population and can start at any point in life- childhood or adulthood. It most often appears as pink scaling patches or plaques. Usually these are found on knees, elbows and the scalp. However, it can occur anywhere from head to toe. I find the most common trigger by far and away is stress. I tend to tell patients to think of it as a ‘check engine light’- at times the flares will tell you that you are taking on more than you can handle! For many, however, there is no rhyme or reason to the flares. Other common triggers are injuries to the skin (psoriasis can often show up in surgical scars), medications can trigger it, infections (strep throat is linked to a particular type of psoriasis called guttate), weather changes, smoking and alcohol use. Irritant or allergic contact dermatitis can result from hair products, styling agents, and hair dyes. Preservatives and fragrance can lead to scalp rashes in some cases. Allergies to some hair dyes or irritation from an accumulation of product can result in itching and inflammation on the scalp. Even some active ingredients in hair product, such as tea tree oil, that are added to manage other scalp conditions such as seborrhea can cause allergic reactions in as many as 1 to 2 % of the population. Itching and flakiness of the scalp is a sign of inflammation and dryness. The skin on our scalp is relatively thick with a dense population of hair follicles- each with a sebaceous or oil gland at the base giving it much resilience from drying out too quickly. As we get older, our skin thins and the density of hair follicles reduces. This makes our scalp more susceptible to drying out from season or temperature changes alone. To treat itching or flaking over the counter ingredients in shampoos and topicals are usually targeting the inflammation, dryness and/or scaling in the scalp. Most of these are meant to be used two to three times weekly to address the underlying triggers of inflammation or to add moisture back to the scalp. Zinc pyrithione: Zinc pyrthione is an antimicrobial ingredient in many over the counter scalp shampoos or treatments. It targets the yeast and bacteria on our scalp that can trigger inflammation. https://www.ncbi.nlm.nih.gov/pubmed/26885780 Charcoal: Charcoal has become a popular ingredient for products to include when targeting excess oil or impurities. Although I could not find a single medical study to show the effectiveness of charcoal in treating scalps directly, I can find potential benefits to using products that contain it. What is charcoal? Activated charcoal used in products and in medicine is made by heating substances rich in carbon such as wood, sawdust, coconut shells, etc. This is an interesting process because it allows the carbon to become more adsorbent. Adsorbent means that it can bind more molecules. In medicine activated charcoal has been used to treat overdoses and poisonings as it can adsorb these toxins quickly. It has been used in wound healing in addition to a number of other uses. Charcoal applied to the skin is overall harmless and is not likely to irritate the skin. The theory behind adding it to products is that it may possibly absorb extra oil from the skin. If you have found a benefit in treating your scalp with charcoal containing topicals then it is perfectly ok to continue. It would likely be best for people that have an oily scalp. It is a milder alternative to help reduce the oiliness without excessively drying the skin or hair. Coconut oil Coconut oil is gaining a lot of attention in skin care products. It is a proven emollient that can effectively hydrate the skin. It also has antimicrobrial and anti inflammatory properties. These can beneficial for dry flaky scalps to help hydrate and improve scaling or flaking to the scalp. Apple cider vinegar I don’t think a day goes by where a patient doesn’t tell me that they used apple cider vinegar to treat something! ACV has anti yeast properties and has been used to even treat diaper rash. Seborrheic dermatitis is thought to be related to yeast that overgrown on our skin. It can often be added to scalp exfoliators to help address the underlying yeast that triggers inflammation resulting in scaling. Tea tree oil Tea tree oil has become one of the most common ingredients to find in skin care products. It is known for its antimicrobial and antiseptic properties in it’s activity against bacteria, viruses, fungus, mites, etc. When added to scalp exfoliators it is likely addressing some of the underlying triggers for scalp inflammation that result in scaling and itching. The only caution is that it does have about a 1-2% chance of causing a contact dermatitis in those that use it. If using a product that has tea tree oil and your itching and flaking is getting worse, it’s important to take a look at your products and make sure they are not making it worse! Salicylic acid Salicylic acid breaks apart superficial skin cells to help remove dead skin cells from the surface. It is used in acne medications but can also be found in higher concentrations in wart treatments. It can be effective without being too irritating. In scalp products it can help remove excess dry skin and scale. ‘Acne’ of the scalp falls under a category of a group of conditions thought to share the same cause called the ‘follicular occlusion tetrad’. This group includes acne, hidradenitis suppurtiva, pilonidal cysts, and dissecting cellulitis of the scalp. This last diagnosis is what ‘acne’ of the scalp would be classified under. The reason for this is that true ‘acne’ is triggered by clogged pores, followed by inflammation deep in the skin, and the potential for scarring. Although bacteria may be found and may play a role, the cause of these conditions is thought to be possibly autoimmune or the result clogged or blocked follicles that trigger inflammation. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4228650/ The management of true acne of the scalp is usually through medications by mouth such as isotretinoin, antibiotics and possibly injection of steroids into the scalp given the high risk of scarring and permanent hair loss. This is a deep process at the root of the follicle and topicals simply cannot effectively manage it. There are multiple triggers for folliculitis of the scalp. Most cases of breakouts in the scalp are actually folliculitis. The difference is that the trigger is not necessarily clogged pores or comedones that trigger acne. The trigger is more commonly inflammation at the base of the hair follicles. This inflammation can be the result of bacteria, yeast, mites and/or autoimmune triggers. The reasons commonly attributed to scalp folliculitis are heat, sweating, humidity, hormonal changes- conditions that alter the pH of the skin to permit the overgrowth of yeast, bacteria, and mites. Bacterial folliculitis is the result of bacteria, most common staphylococcus, findings its way into hair follicles resulting in inflammation and pustules forming. The bacteria can find its way in from the environment. Sweating, hats or head gear, and itching can result in this common bacteria finding its way into our hair follicles. Yeast folliculitis can be triggered by pityrosporum which is thought to result from overgrowth from heat or sweating. Mites, demodex mites in particular, have been known to trigger scalp folliculitis as well. Folliculitis decalvans, lichen planopilaris, and acne keloidalis nuchae are inflammatory conditions of the scalp that are thought to be autoimmune in nature and can result in pustular eruptions on the scalp that may lead to scarring hair loss. Shampoos containing zinc pyrithione are effective as this ingredient has had proven antimicrobial qualities. Selenium sulfide containing shampoos are beneficial as selenium sulfide has been shown to be both antimicrobial and an effective treatment for hyperkeratosis or thickening of the skin. By addressing the buildup and the yeast and bacteria that contribute to scalp acne, this is a safe and effective approach to this common problem. https://www.ncbi.nlm.nih.gov/pubmed/30203232 Given the inflammatory component of many cases of scalp acne, it is important to have your scalp evaluated by your dermatologist for an accurate diagnosis to guide treatment. If there is an autoimmune component or significant inflammatory component topical steroids or injections of steroids into the scalp may be necessary to control these conditions more effectively and avoid scarring that can result in permanent hair loss. A truly sensitive scalp has been found to likely be the result of a combination of factors with an altered pH, overgrowth of certain bacteria (P acnes in many cases), and excess oil or sebum production. (https://www.ncbi.nlm.nih.gov/pubmed/30084158) A good hair mask will address these concerns. Coconut oil, argan oil and shea butter are good ingredients to help re-hyrdate the scalp and reduce itching and scaling. Melt 2 tbs of coconut oil with 1 tbs of shea butter in a microwave safe dish. Mix in 1 tsp of argan oil. Peanut oil has been used in a prescription product for psoriasis for years. It has vitamin E, antioxidants and moisturizing properties. The recipes for a peanut oil hair mask are a little more straightforward with about 4 tbs of peanut oil mixed with several drops of lemon juice before applying to the scalp. https://www.ncbi.nlm.nih.gov/pubmed/?term=peanut+oil+scalp
Given the wide range of causes of hair and scalp disorders and the potential for permanent hair loss if not managed appropriately, I strongly recommend an evaluation by a Board Certified Dermatologist to accurately diagnose the cause of your condition. If a treatment plan is started early, we can often save people from wasting money on unnecessary products or products that can potentially worsen the condition in addition to helping you navigate your choices in the hair care aisle! I find that the package labels for hair products are poorly understood by consumers. It helps to understand your choices!