Q: I am a 32 years old male and have been diagnosed with Prurigo Nodularis (PN) after a skin biopsy. I have a lot of skin rashes on my legs and hands with watery fluid. My problem started almost three years ago when suddenly some small bumps developed on my right leg’s skin. They were very itchy and got worse because of scratching and similar scabs developed later on my left leg and arms. Soon, I realized that I am allergic to many food items, which I used to have heavily. I also used to indulge in over-eating. Now, if I take any milk product (such as, ice-cream, chocolates, ghee, butter), oily food or rice, within a few minutes of taking such a diet, I start experiencing heavy itching. This is mostly during the night hours. If I drink water or pour water on the affected area, the itching stops. I read somewhere on the Internet that the main cause for such a problem is skin infection and then, I got my screening tests for HIV-I and HIV-II. The tests reports came out to be non-reactive (value-0.21). Does PN happen to those with HIV Infection? But, I never had any sexual relationship. Can you please tell the major cause of PN? Does PN happen because of food allergies?

A:Prurigo nodularis (PN) is a skin condition in which hard crusty lumps form on the skin that itches intensely. PN may itch constantly, mostly at night, or only when a light brush of clothing sets off a round of severe itch. For many, itching only ends when the PN is scratched to the point of bleeding or pain. PN sore is hard and usually about a half inch across. The top is dry and rough and often scratched open. Old white scars are often found nearby from old sores. They tend to be in the areas most easily reached: arms, shoulders and legs. There may be just a few or dozens. PN, however, is actually the end result of scratching. Scratching causes the skin nerves to thicken, and when stimulated, they send unusually strong itch signals. Scratching is like exercise for the nerves, the more it is done, the stronger they become. What starts the scratching going at first can be different from one sufferer to the next. Once PN set in full force the end is similar, and it may last years. Factors triggering PN, and keeping it going include nervous and mental conditions, reduced function of the liver and kidneys, and skin diseases such as eczema, bullous pemphigoid and dermatitis herpetiformis. In many, the true cause is never found. Treatment is difficult. Due to the intensity of the itch patients often go from doctor to doctor looking for relief. No one treatment is always effective and several treatments may need to be tried. Initial treatment is often potent prescription steroid creams. If these help, a milder cream can be used for longer-term control. Antihistamine tablets are often added for additional relief. Intralesional steroid injections, anti-depressant pills, and non-prescription Zostrix cream helps many of those not improved with the usual treatment. Severe and resistant cases can be controlled with cryotherapy (freezing the sores with liquid nitrogen spray), oral steroids or PUVA. Of course, try not to scratch the spots. In resistant cases blood tests and biopsy of the sores may be needed to look for a cause driving the PN. I want you to specially understand that your condition is never a reflection of HIV disease. Protect yourself from mosquito bites and request your doctor to please think in terms of an allergic condition like Atopy.