Dr Margaret answers e-mailers' embarrassing problems in this biweekly problem page.

Pigmentation

Dear Dr Margaret
Under my arms and between my legs the skin is very much darker than elsewhere on my body. This is very embarrassing in the summer when I am swimming. What is it and how can I deal with it?

Dear Dr Margaret
Is it abnormal for a female to have much darker skin around the private area? Does it mean something is wrong?

It is perfectly normal for the skin under the arms and between the buttocks (and around the vagina in women) to be darker than elsewhere on the body. So usually it does not mean that anything is wrong. However, there are two important medical conditions in which the skin becomes darker - 'acanthosis nigricans' and 'haemochromatosis'.

Acanthosis nigricans is the medical term for dark brown/black areas of skin that have a velvety texture. There are often tags of skin on or around the affected areas. Acanthosis nigricans can occur under the arms, in the groins, on the back of the neck and around the opening of the vagina (vulva). It is most common in people with dark skin - more than 1 in 10 African Americans and one in 20 Hispanic Americans have it, but only 1 in 100 white Americans.

Acanthosis nigricans may be a sign that the body's metabolism is out of balance. For example, many people who have it are very overweight, with a tendency to diabetes. It can also be a sign of hormone problems (such as polycystic ovary syndrome. In rare cases, it can be a sign of an internal cancer. So if you think you have acanthosis nigricans you need to see your doctor for a general check-up, including a diabetes check.

If a very overweight person with acanthosis nigricans loses weight, the dark patches usually fade away. Otherwise, retinoid creams (as used for acne) may help.

In haemochromatosis, the skin over the whole body becomes darker. In pale-skinned people, it makes the skin look a slate-grey colour. Haemochromatosis is caused by a disorder of the metabolism of iron in the body. It can lead to many health problems (including liver damage), so it needs specialist treatment.

Any more questions?
Do you have any questions about embarrassing problems? If so, send an email to info@healthpress.co.uk. I am sorry that I cannot send you an individual reply, but I will try to answer some of them on this page.

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