Skin colour

Dear Dr Margaret
Since I was young, the skin around my armpits is much darker than my normal skin colour. I feel I cannot wear a sleeveless top or swimwear. Can this problem be removed by lasering? Should I go to a specialist for help?

It is quite common to have darker skin in areas where there are skin folds or creases, such as between the buttocks, around the vagina (vulva), below the breasts and also in the armpits. Usually this is perfectly normal (and is probably inherited), and does not signify ill-health. I suspect this the case for you, because you have had the darker skin since you were young.

However, darkening of the skin can sometimes be a sign of illness. At medical school, we all learnt about a condition called Addison’s disease, in which the adrenal gland is underactive. In Addison’s disease, the skin becomes darker with a muddy appearance, especially in sun-exposed areas, and on the palms, soles, armpits and near the anus. This condition is unusual, but is serious and needs treatment. An overactive thyroid gland can also cause darkening of the skin, especially in people with darker complexions. If you are overweight and the darker skin is thickened, and velvety or leathery in texture, it would be a sign that you are heading towards developing type 2 diabetes.

Skin damage from persistent scratching or from eczema (dermatitis) can cause darkening of the skin as it heals.

So what should you do about it? Firstly, you need to check with your doctor that you do not have any of the conditions I have mentioned above, or any other cause. If your doctor gives you the all-clear, and you are really troubled by the darker skin, you should consult a skin specialist (dermatologist). There are some special medications to reduce skin discoloration, but you need to obtain expert advice from the dermatologist about these. It would be very foolish to try any ‘skin bleaches’ you see advertised on the internet or elsewhere; some of these can cause inflammation of the skin and make the problem much worse. Lasers are occasionally used to treat excessive skin pigmentation, so this is something you could discuss with the dermatologist.

Information sources
Stulberg DL et al. Common hyperpigmentation disorders in adults. American Family Physician 2003;68:1955–60 and 1963–8.
Preston P, Zaki I. Pigmentary disorders - possible causes of change. Dermatology in Practice 2003; 11(3):6–10.
Goodheart HP. Hyperpigmentation disorders. Women’s Health in Primary Care 1999;2:923–9.