Treating seborrheic dermatitis in androgenetic alopecia: Make it a part of the plan

Treating seborrheic dermatitis in male pattern balding 

Seborrheic dermatitis is a common flaky scalp condition that affects about 1 out of every 15 people. I describe the condition 'seborrheic dermatitis' to my patients as being a distant cousin of 'dandruff.' Individuals with seborrheic dermatitis have red, flaky, greasy scalps. The flakes may be yellow or white. When it's mild, most don't even know they have seborrheic dermatitis. Others notice a bit of itching, especially if they don't wash their hair every day. Seborrheic dermatitis, like dandruff, is influenced to a large degree by a yeast that lives in our scalp called Malassezia. But this yeast isn't the whole story, and a variety of genetic, environmental and hormonal factors seem important. 

Is seborrheic dermatitis harmful? If not, why treat it?

For the most part, seborrheic dermatitis is not harmful.   I pay attention to seborrheic dermatitis in both my hair loss patients and my hair transplant patients and treat it if the condition is present. I do this for a couple of reasons:

1. Poorly controlled seborrheic dermatitis increases the proportion of hairs that are in the resting phase of the hair cycle (telogen phase). If we want to build density and drive improvement, we need growing hairs!  While seborreheic dermatitis usually doesn't cause hair loss or shedding, poorly controlled seborrheic dermatitis can. In patients with many miniaturized hairs undergoing hair transplant procedures, I believe that encouraging these hairs to be in the growing phase rather than the telogen phase, reduces 'shock loss.' I advise using an anti-dandruff shampoo (see below) three or four times per week for 6 weeks leading up to the transplant and then resuming 2 weeks after the hair transplant

2. Treating seborrheic dermatitis with anti-dandruff shampoos may actually help hair growth. I am reminded of two studies  - one from 1998 and one from 2003 - which showed the zinc pyrithione shampoo as well as ketoconazole shampoo actually helped promote hair growth in men with androgenetic alopecia.  Whether the ingredients themselves are hair growth promoting or whether getting rid of the yeast reduces inflammation that helps drive hair growth is not 100 % clear, but it seems that the latter is more likely.  Regardless, I recommend treating seborrheic dermatitis aggressively when it's present. 

Treatment of seborrheic dermatitis

Fortunately, treating seborrheic dermatitis is usually simple, with any of the commercially available shampoos:

a) zinc pyrithione (i.e. Head and Shoulders and others)

b) selenium sulphide (i.e. Selsun Blue and others)

c) ketoconazole (i.e. Nizoral and others)

d) tar-based shampoos (i.e. T-gel and others)

e) ciclopirox olamine (i.e. Stieprox and others)

References

1. Pierard-Franchimont et al. Ketoconazole shampoo: effect of long term use in androgenetic alopecia. Dermatology 1998; 196; 474-7

2. Berger et al. The effects of minoxidil, 1 % pyrithione zinc and a combination of both on hair density: a randomized controlled trial. Br J Dermatol 2003; 149: 354-62