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Why do I get a rash on my arm when I menstruate?

I am a 34 year old female and mother. Every month I begin to menstruate I get a rash in the inside of my elbow and lower arm only on my left arm. It itches so bad and is little red bumps. When I stop menstruating, it goes away and returns the next month. I put rubbing alcohol on it to take the itch out, but am embarrassed to go to my doctor. What could it be?
There is a rare condition described in a few case reports called autoimmune progesterone dermatitis. Basically this is a condition in which a patient develops antibodies to progesterone, one of the sex hormones that peaks in the body right before menstruation. The patients who have this condition tend to have an itchy, cyclical rash that typically begins a little bit before the menstrual period begins and ends a few days in. Most cases of the rash are quite mild, and they can be managed by simple application of a topical steroid cream and oral antihistamines to control the itch. You should see you doctor, however, before beginning therapy to confirm that this is the likely condition. Another possibility would be that you simply have eczema, which is a condition characterized by excessive dryness, redness, and itching of the skin. This may be worse with menstruation simply because your body is more sensitive at this time. Fortunately, the therapy for eczema is the same as for autoimmune progesterone dermatitis (topical steroid creams), so the exact diagnosis might not matter too much. If the symptoms worsen or if you have any wheezing or other respiratory allergy symptoms you should definitely see your doctor.
This answer is for general informational purposes only and is not a substitute for professional medical advice.
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