This article examines the relationship between seborrheic dermatitis and hair loss in detail. What might be the cause, how we may be able to reverse it and potential ways to speed up recovery.
The first section examines the idea that the cause of hair loss may be attributed to the malassezia fungus. Next, potential approaches to treatment are reviewed. After this, other potential factors that may be fueling the hair loss are considered. And finally, several popular hair growth approaches are analyzed.
Table of Contents
- 1 The Fungus Most Commonly Responsible for Seborrheic Dermatitis and Accompanying Hair Loss
- 2 Fighting the Malassezia Fungus to Help Restore Normal Hair Growth
- 2.1 Pyrithione Zinc Is One of the Most Popular Anti Malassezia Solutions
- 2.2 Ketoconazole (Nizoral) May Be Better for Hair Growth
- 2.3 Raw Honey for Malassezia Control
- 2.4 Using Natural Anti-Fungal Fatty Acids Against Malassezia
- 2.5 Other Anti-Fungal Solutions
- 2.6 Tons of Other Not So Well Documented Methods
- 3 Ways To Stimulate Hair Growth After Fungus Has Been Controlled
- 3.1 Improving Circulation to Improve Growth
- 3.2 Correcting Nutritional Deficiencies May Reverse Hair Loss and Improve Growth
- 3.2.1 Biotin and It’s Role in Hair Growth
- 3.2.2 Zinc and It’s Illusive Connection to Hair Loss
- 3.2.3 Iron May Improve Hair Growth in Cases of Deficiency
- 3.2.4 Over Supplementation Can Actually Lead to Hair Loss
- 3.2.5 Additional Nutrition Related Findings
- 3.2.6 Summary of Nutrition for Hair Growth
- 3.3 Most Popular Methods That Specifically Target Hair Growth
- 4 The Connection Between Androgens, Seborrheic Dermatitis and Hair Loss
- 5 Conclusion
The Fungus Most Commonly Responsible for Seborrheic Dermatitis and Accompanying Hair Loss
Hair loss is a common side effect of seborrheic dermatitis. And this is especially true, if inflammation is allowed to spiral out of control and flaking occurs on a large portion of the skin surface. Yet, the link between seborrheic dermatitis and hair loss remains illusive.
Is seborrheic dermatitis directly responsible for the hair loss or are the underlying factors of seborrheic dermatitis causing the hair loss?
The majority of medical literature and even online discussion typically concludes that the majority of seborrheic dermatitis is caused by the malassezia fungus. This fungus is considered lipophilic, meaning that it feeds off of fats (lipids). And this is where the problem begins.
Normal skin uses sebum (secreted from the hair follicles) to protect itself from the environment and retain moisture. And a significant part of this sebum, is made up of lipids. And these exact lipids that our skin utilizes for its protection, can be a prime food source for the malassezia. This makes the fungus extremely common and present even on the skin of individuals who are not affected by seborrheic dermatitis.
The issue is that in some individuals this fungus can cause seborrheic dermatitis, which can often be accompanied by significant hair loss. In these cases, the fungus appears to disrupt the skins natural defense mechanism and in some cases, invade the hair follicles (from which the sebum is secreted) (source). And this invasion of the hair follicles may literally be at the root of the hair loss that comes along with seborrheic dermatitis.
Perhaps Your Issue is Not Malassezia
The majority of this article is focused on discussing hair loss that accompanies malassezia infestation. In some individuals, the issues may not actually be caused by malassezia, but another bacteria/fungus/micro-organism. In these cases, much discussion relating directly malassezia might not be applicable. Nevertheless, many points may still be relevant.
Fighting the Malassezia Fungus to Help Restore Normal Hair Growth
Based on the theory discussed above, the most direct way to reverse hair loss and improve hair growth would be to fight the malassezia fungus invading the hair follicle. This should restore follicle health and pave the way for normal hair growth.
This next section will discuss the most wide-spread methods that have been documented to be effective against the malassezia fungus. The first two methods will be the more researched ones, but rely on the usage of commercial anti-fungal agents. After these, focus will shift towards more natural methods that are popular across the internet (some of which do have medical research behind them as well).
Pyrithione Zinc Is One of the Most Popular Anti Malassezia Solutions
Pyrithione Zinc is one of the most popular anti-fungal agents used against the malassezia fungus. And the shampoo that contains it (Head & Shoulders), is actually one of the most popular shampoos in the world.
Regular usage has been shown to be effective at reducing malassezia colonies on the skin, restoring normal hair growth, and returning the skins ultrastructure to normal (source). But it is rather difficult to find studies that actually examine it’s effect on hair growth in individuals experiencing strong malassezia infection, instead most studies on its effect on hair loss/growth are more general in nature.
Pyrithione Zinc and Hair Growth – Highlights from Medical Literature
Overall though, pyrithione zinc is one of the most documented anti-fungal agents shown to be effective against malassezia. And here are some interesting points gathered from various research papers:
- Hair quality and overall performance on scaling and itching appears to be better for pyrithione zinc then ketoconazole (source)
- Appears to normalize epithelial keratinization (formation of outer most layer of skin) and/or sebum production, resulting in improved scalp health (source)
- Selenium sulfide appears to be superior to pyrithione zinc in reducing malassezia numbers (source)
- Regular shampoo usage (2-3 times per week) may result in a decrease in hair shaft diameter (hair thickness), but a significant improvement in new hair growth was noted (source)
One study (source) that tried to examine the effects on hair growth concluded that the daily usage resulted in a significant overall increase in total visible hair counts. But the issue with this study is that individuals with seborrheic dermatitis, psoriasis and other scalp infections were specifically excluded. As a result, this study may not be a good representation of how significant results may be for those actually suffering from a malassezia infestation.
Ketoconazole (Nizoral) May Be Better for Hair Growth
Another popular anti-fungal agent for the treatment of seborrheic dermatitis is ketoconazole. Most medical literature seems to indicate that it is actually more effective then pyrithione zinc (source). In addition to this, ketoconazole usage appears to be more popular among individuals trying to combat premature balding.
This would indicate that ketoconazole may be a better option for control of malassezia and restoration of hair growth then pyrithione zinc. However, one studies concluded that individuals testing both products actually preferred pyrithione zinc in overall effectiveness.
Ketoconazole and Hair Growth – Highlights from Medical Literature
- On average, individuals reported better results from pyrithione zinc as opposed to ketoconazole in terms of overall performance on hair health (hair-combing ease, smoothness, frizz, etc) (source)
- In an experiment carried out on mice, it appeared to stimulate hair growth, and when it was integrated into a shampoo (opposed to a regular lotion/ointment) penetration was enhanced (source)
- Using ketoconazole containing shampoo 2-3 times a week for 6 months had no change on hair density, but had the most drastic (a reduction of almost 20%) impact on hair shedding from all anti-dandruff shampoos tested (source)
- Regular usage was shown to increase hair shaft thickness while also producing a small decrease in sebum output at the skin surface (source)
Raw Honey for Malassezia Control
In Arab medicine, honey has long been used for treatment of fungal infections of the skin and modern medical literature has highlighted its antifungal activity against malassezia and broad antimicrobial properties (source). This makes honey a prime candidate for an all natural approach to treating malassezia infection and allowing for a healthy scalp environment.
Honey treatments have been discussed previously on this website in significant length. These can be found here: Basics of Treating Seborrheic Dermatitis with Raw Honey
Raw Honey and Hair Growth – Highlights from Medical Literature
Medical literature regarding any potential impact that honey may have on hair growth is fairly limited.
- One paper mentioned that honey application on a dog had restored had restored hair growth on skin severally damaged from a house explosion (areas of skin without treatment did not have any hair growth) (source)
- In one study of 20 patients with seborrheic dermatitis, regular treatment with honey resulted in subjective (self-reported) improvement in hair loss (source)
- A patent filed back in 2000 suggests that a combination of honey, vinegar and water may aid in stimulation of new hair growth and prevent/minimize hair loss, but this was note the core of the patent (source)
Raw Honey and Hair Growth – Online Search
If we don’t restrict our search to medical literature, the internet is full of blog posts and forum posts that discuss honeys potential in stimulating hair growth. These will not be discussed here as there doesn’t appear to be enough valuable discussion or user validation. However, the amount of discussion on this topic appears to further validate the idea of using raw honey to aid hair growth.
Using Natural Anti-Fungal Fatty Acids Against Malassezia
There are also several fatty acids found in nature which appear to have significant anti-fungal activity against a variety of fungi (source). And one of the most popular of these, is caprylic acid.
Caprylic acid often used is the emollient (oily) component of many skin care products. And when it is used at an adequate concentration, it’s been shown to have broad antifungal activity against a variety of malassezia species (source).
If hair loss that accompanies seborrheic dermatitis can be reversed once a healthy scalp microflora is restored, one could argue that caprylic acid may be beneficial in restoring normal hair growth. However, there does not appear to be any medical literature which evaluates it’s effectiveness in the area of hair growth stimulation.
Other Anti-Fungal Solutions
Earlier, two of the most popular anti-fungal solutions were discussed (pyrithione zinc and ketocanozole). In addition to these, there is a significant amount of other anti-fungal solutions currently available. Some of these are prescription based, while others are sold over the counter. These include:
And some which are not officially considered anti-fungal:
- Selenfium Sulphide
- Lithium Succinate
- Benzyol Peroxide
- Propylene Glycole
These agents are noted here for reference, however we will not be discussing these here in much detail.
Tons of Other Not So Well Documented Methods
In addition to the items discussed above, there are tons of other potential methods of fighting the malassezia fungus. Some of these have a good amount of discussion online, but the research behind these is fairly limited:
Ways To Stimulate Hair Growth After Fungus Has Been Controlled
Once the scalp micrflora is brought back to a healthy state, hair growth should naturally restore to normal. But if hair loss was significant, increasing the rate of restoration may be helpful. This section will discuss some of the potential methods this can be achieved.
Improving Circulation to Improve Growth
As with the majority of bodily functions, improving blood and nutrient delivery should increase the rate of repair and cellular activity. Thus, increasing circulation on our scalp and improving nutrient delivery to our hair follicles should in theory increase the rate of growth.
L-arginine is a non-essential amino acid (protein) that humans typically obtain from diet. Athletes often use it as supplement based on the idea that it can increase blood flow and improve the recovery rate of muscle tissue.
The area which is most interest to us, is the fact that nitric oxide is produced from l-arginine. And nitric oxide appears to have both anti-fungal potential (source) and the ability to mediate vasodilatation (widening of blood vessels) (source). Thus, improving the availability of l-arginine at the skin surface may improve local nitric oxide production resulting in improved blood flow.
Many Hair Restoration Shampoos Contain L-Arginine
Luckily, finding products that contain l-arginine is not very difficult. Many of the shampoos currently sold under various labels and aimed at hair restoration contain l-arginine. Some examples include:
- Andalou Naturals Moisture Rich Shampoo (the shampoo I use)
- LOreal Paris Arginine Triple Resist Reinforcing Shampoo
- Suave Men 2 in 1 Shampoo and Conditioner
- Batiste Dry Shampoo, Strength and Shine
- Avalon Organics Peppermint Revitalizing Shampoo
The biggest issue is that products typically do not specify the relative amount of ingredients they contain. Plus, shampoos are quickly washed off. These factors, make it rather difficult to determine if a shampoo will really provide enough l-arginine to achieve any beneficial effects. Perhaps, a leave-on product that species the relative amount of l-arginine it contains, may be more beneficial.
Can a Scalp Massage Help Improve Hair Growth?
Something as simple as a scalp massage may also be beneficial for improving blood flow to the scalp. The it has many positives: it’s completely free, can be done as frequently as you like and it feels amazing.
The research in this area is fairy limited, but there are patents that describe using a head massage device to stimulate blood flow and improve hair growth. Here is the most relevant one:
And there was one case study published by Cameron University in which massage, relaxation and monetary reward resulted in improvement/reversal of overall hair loss (source).
Correcting Nutritional Deficiencies May Reverse Hair Loss and Improve Growth
Many believe nutrition plays a large role in determining the growth rate and quality of hair. The research on this subject is quite sparse and mainly outlines the fact that deficiency of some nutrients (not very common in the modern world) may lead to hair loss/thinning. Yet, this does not stop various blogs and forums across the internet making a large range of recommendations on which foods and supplements can improve hair growth.
This section will look at some of the more popular nutrients that relate to hair loss/growth and make corresponding recommendations.
Biotin and It’s Role in Hair Growth
Most of the claims that biotin can regrow hair are anecdotal (unproven). A biotin deficiency may be both genetic (individual’s genes) or acquired (dietary and lifestyle choices). The acquired form is very rare in adults and typically only occurs due to alcoholism, malabsorption, pregnancy (source), but can also be a result of unusual dietary choices.
The most frequent cause of acquired biotin deficiency in adults, is the consumption of raw egg. This comes from the fact that the egg white contains a protein called avidin. This unique protein can bind with biotin and prevent its absorption by our bodies. Luckily, cooking denatures avidin and in this state, it does not appear to bind (preventing it’s usage by our bodies) to biotin (source).
What Does Research Say About Biotin
Actual research on biotin supplementation and it’s effect on hair loss is quite sparse. A small study on 46 women showed no results (source), and no clinic trials exist showing is efficacy (source). Yet, there has been some mention of its potential usage based on it’s positive effect on brittle nails (source). But, this really is not enough to warrant it’s general recommendation.
Most research on this subject is mainly concerned with babies and small children. Chances of deficiency at this stage of life are greatest.
If the deficiency is genetic, it can be fatal during the first 6 weeks of life it and surviving infants have extensive dermatitis and severe alopecia (hair loss) (source). If the genetic deficiency becomes pronounced after the first 3 months of life, some children may experience small (less then normal) amounts of hair growth, but some may not have any hair growth at all.
The acquired form is quite rare as biotin is present in a large variety of food and synthesized by bacteria within the gut itself.
Zinc and It’s Illusive Connection to Hair Loss
There are tons of articles on the internet which state that a zinc deficiency can cause hair loss. And that supplementation can improve hair growth. Yet, the medical literature on the subject shows mixed outcomes and results are never as clear cut as online articles may suggest.
One study, done in 1981, tested the effectiveness of zinc sulphate supplements on 46 hair loss patients and concluded that no improvement occurred (source). However, a more recent study carried out in 2009 on patients diagnosed with alopecia areata (an auto-immune disease that causes balding in random patches) showed promising results (source).
There are a number of smaller medical case studies which do show some potential for zinc to reverse hair loss:
- Diffuse alopecia in a child due to dietary zinc deficiency
- Reversal of Hair Loss following Vertical Gastroplasty when Treated with Zinc Sulphate
- Clinical response of alopecia, trichorrhexis nodosa, and dry, scaly skin to zinc supplementation
But case studies on single patients do not provide enough evidence to warrant any general recommendations.
Overall, it is likely best to ensure we obtain enough zinc by eating a well balanced diet. The best sources of zinc are seafood and meat. Plant sources such as seeds, beans, peas and lentils do provide some zinc. But, vegetarians are often recommended to supplement as their diets typically result in low zinc intakes.
Iron May Improve Hair Growth in Cases of Deficiency
Iron is one of the worlds most common nutritional deficiencies. And it can results in diminished intellectual performance and decrease resistance to infection (source).
One of the earliest studies was carried out over 40 years ago (in 1963 to be exact). In this study scientists demonstrated that an iron deficiency could be the direct cause of of hair loss in women and correction therapy was used to reverse this hair loss (source). This study sparked interest in using iron to reverse hair loss. However, larger more recent studies failed to show any direct connection between iron deficiency and hair loss:
- Iron status of patients with alopecia areat
- No association between serum ferritin levels >10 microg/l and hair loss activity in women
- Iron deficiency and hair loss: the jury is still out
Even though there does appear to be some cases in which iron may contribute to hair growth, there is not enough evidence to suggest universal screening for iron deficiency in hair loss patients (source).
The easiest way to avoid iron deficiency is through adequate dietary intake. And similar to zinc, animal sources of iron (such as various meats and seafood) appear to be preferable to plant sources and iron fortified foods (source).
Over Supplementation Can Actually Lead to Hair Loss
Sometimes less is more. Excessive amounts of certain vitamins and nutrients has actually been documented to result in hair loss.
The most established of these relates to excessive vitamin A intake (source). However, some studies suggest too much of vitamin E, selenium (source) and/or folic acid (source) also have negative results. As a result, the best approach to prevent deficiency is likely through a balanced diet and not abusive supplementation.
Other nutritional deficiencies that appear to cause hair loss and documented in medical literature, include:
However, the internet is also full of recommendations which are not based on science. These typically result from the recycling of information from potentially unreliable sources. If you conduct your own research, be vigilant and look for information backed by at-least some sort of research.
Summary of Nutrition for Hair Growth
Research appears on nutrition and its effect on hair growth typically examines how various deficiencies may cause hair loss. And correcting these deficiencies can reverse hair loss and return hair growth to normal. However, supplementation without medical testing may actually be counter productive.
Perhaps the best approach is to simply ensure your diet has a large variety of healthy food choices and is suitable for your unique lifestyle.
Most Popular Methods That Specifically Target Hair Growth
In addition to the items described above, there are tons of discussed treatments found across the internet which target hair loss/growth directly (irrespective of malassezia). The most popular of these, is drug by the name of minoxidil and an all natural oil derived from castor beans. These approaches are discussed next.
Minoxidil for Stimulating Hair Growth
Minoxidil is one of the most famous hair growth stimulates known today. It’s results are so pronounced that in the 80’s some doctors started prescribing it to balding patients before it was ever approved by the FDA for treatment of baldness.
The biggest downfalls, is that results take time to be noticeable and that once treatment is stopped, hair loss often returns (source).
Today, minoxidil products are widely available and can be purchased without any prescription. Costco carries it’s own Kirkland version, Wal-Mart has it’s own Equate version, and Amazon has a ton of offerings from various companies. And the reviews for the majority of these minoxidil products are quite favorable, further affirming its effectiveness.
Minoxidil and Potential Side Effects
As with most drugs, minoxidil has it’s own set of potential side effects. The biggest one is that in some individuals, it may produce the opposite effect and result in temporary hair loss. Other side effects include potential skin irritation, unwanted hair growth in other parts of the body, and unwanted thickening and darkening of hair.
Minoxidil – Highlights from Medical Literature
- A solution containing only 1% minoxidil was shown to be effective for hair regrowth, but a 5% solution was more effective (source)
- When 5% foam was compared to a regular 2% solution, results were practically the same (source)
- In some patients, minoxidil can cause atopic dermatitis and scaling of the scalp and potential exacerbation of seborrheic dermatitis. In patients tested, the cause was not the active minoxidil, but the other ingredients of the formulation such as propylene glycol. Switching to alternative minoxidil preparations appeared to resolve symptoms (source)
Castor Oil for Hair Growth
Many blogs and forums tout castor oil as being one of the most effective natural treatments for improving hair growth. And many individuals claim that it has been used for decades.
The active component is the ricinoleic acid which believed to increase topical blood circulation.
The issues is that medical literature on this subject is practically non-existent. The most relevant item I could find was a review article published in 1982 that summarized the various uses of castor oil (source). It mentioned that the oil is used in Ethiopia to combat seborrhea and tinea (another fungal skin infection). And that an alcoholic solution has been recognized in Italy to have anti-seborrheic action and favor the growth of hair.
Adding Rosemary Essential Oil to Castor Oil
Many sources also suggest that adding rosemary essential oil will further improve castor oil’s effectiveness. But once again, research on this subject is very sparse and the closest item I managed to find was a patent aimed at stimulating hair growth which included a rosemary extract (source).
Caffeine to Stimulate Cellular Growth
Some researchers suggest that topical application of caffeine can improve barrier function (source), increase hair shaft diameter (source) and stimulate/promote new hair growth. And shampoos containing caffeine appear to be excellent an method for delivering it into the hair follicles (source).
One study showed that regular application of a caffeine containing preparation reduced the number of hairs extracted using a pull test by 8.14% after 2 months and by 15.33% after 4 months (source).
While another study concluded that caffeine led to a significant stimulation of hair follicle growth. However, at higher concentrations it may actually have a negative impact on results as it may cause over-stimulation, over consumption of energy reserves and exhaustion of proliferation capability (source).
Even though caffeine does appear to hold some value in stimulating hair growth, most studies suggest that further research is needed. Nevertheless , for individuals desperate to improve hair growth, it may be a valuable addition to your regimen.
The Connection Between Androgens, Seborrheic Dermatitis and Hair Loss
The hormones classified as androgens are some of the clearest regulators of human hair growth (source). Because the appear in greater abundance in males, people refer to them as male hormones (as their production is greater in males). But in reality they are actually present in both genders.
Androgens are responsible for the gradual replacement of baby hair (vellus hair) by more thicker, longer and darker hairs during puberty. Yet, they appear to have the opposite effect on scalp hair, causing regression throughout the aging process. Some predisposed individuals are more susceptible to this regression and issues of male pattern baldness arise.
One interesting point, is that androgens are also responsible for activating sebaceous gland activity (during puberty) and regulating it throughout adulthood. Since sebaceous gland activity is closely related to seborrheic dermatitis progression, it is possible that androgens may actually play a crucial role in the in the progression of seborrheic dermatitis itself. And the following three facts further help illustrator this point:
- The malassezia fungus feeds off of sebaceous gland secretions which is regulated by androgens (source)
- Seborrheic dermatitis often appears after puberty and this is the time that androgens become active (source)
- Males have more androgens and seborrheic dermatitis is more common in men than in women (source)
However, even though androgens do appear to be related to both premature hair loss and seborrheic dermatitis, the connection is not clear. Some studies and review papers on seborrheic dermatitis do suggest that androgens may play a role, but most agree that they are not the direct cause (source).
First we examined the potential role that malassezia fungus may play in influencing hair loss. They key takeaway was that malassezia feed off of the oils secreted by our sebaceous glands (many of which are connected to hair follicles) . As a result, malassezia colonies may be more active around the hair follicles and negatively impact normal hair growth.
As a result, reducing the number of malassezia colonies may reverse hair loss and return hair growth back to normal. To achieve this reduction, a significant number of topical anti-fungals (pyrithione zinc, ketoconazole, raw honey, etc) are currently available. And finding one suitable for daily usage may be a necessity (if the skin is failing to naturally regulate it’s microbial environment).
List of Most Common Malassezia Treatments:
- Pyrithione Zinc (Head and Shoulders)
- Ketoconazole (Nizoral)
- Various Azole Anti-Fungals (Bifonazole, Miconazole, Fluconazole, Metronidazole)
- Caprylic Acid
- Selenfium Sulphide
- Lithium Succinate
- Benzyol Peroxide
- Raw Honey
Sometimes individuals may experience a negative reaction to various products. This reaction might not be caused by the active ingredient, but something else contained in the formulation. Thus, it may be worthwhile to compare and evaluate all ingredients while finding a suitable solution.
In addition to this, it might beneficial to aid hair growth by stimulating the hair follicles by inducing vasodilation (improving blood flow). This could improve nutritional delivery and increase the rate of cellular growth/repair. Topical solutions such as the drug minoxidil and a natural oil from the castor bean may also be of value. However, perhaps simply resolving seborrheic dermatitis may be enough to return things back to normal.
Potential Ways to Improve Hair Growth:
- Scalp Massage
- Castor Oil
But in order for any attempts at improving hair growth to be effective, we must ensure that we do not have any nutritional deficiencies which may be preventing progress. The most common of these appear to be iron, zinc, and the amino acid l-lysine. But medical testing for deficiencies is likely the best approach as over supplementation can actually result in the opposite effect (hair loss).
Overall though, I strongly believe that solving seborrheic dermatitis is most likely to resolve hair loss in the majority of cases. But obviously improving the rate of hair recovery definitely can’t hurt. If you found any of this information on seborrheic dermatitis and hair loss/growth helpful, have any additional suggestions or simply want to share your experience, drop a comment below.