I am an 80-year-old man in good health, a vegetarian with well-controlled Type 2 diabetes. Every winter, I suffer from cracked fingertips and peeling skin on the hands. From the Internet, I have learned that a lack of phosphorus can cause such skin problems, and a blood test shows that my blood phosphorus is low. As I regularly eat half of the 30 foods I found listed as being rich in phosphorus, I feel I need a food supplement containing this element. I have been unable to find such a supplement. Any suggestions? G.M., Beit Zayit Veteran Jerusalem dermatologist Dr. Julian Schamroth replies: Many patients suffer from cracked and dry fingers during the winter months. People often call this “winter eczema” or “winter dermatitis.” Interestingly, the frequency of this disorder tends to be greater at the onset of winter rather than during midwinter, which is the coldest time of the year. It is possibly due to the changeover from summer to winter, when the high humidity of summer changes to the dry cold air of winter. Excessive washing may remove some of the natural lubricant oils from the skin and may exacerbate the condition.Winter dermatitis is characterized by red, sore and scaly skin, particularly on the fingertips. In severe cases, cracks or fissures appear on the skin, particularly over the knuckles and under the corners of the nails. If longstanding, the splits may develop a secondary infection.There is no evidence that phosphorus deficiency is related to this or any other form of dermatitis. Besides, such a deficiency cannot explain the seasonal variation in the incidence of this disorder. Vitamins, minerals and essential elements also play no role in the cause, progression or severity of this dermatitis.Treatment depends on the severity of the disorder. In mild cases, where the skin is simply dry, avoiding excessive hand washing and frequent application of an emollient hand cream is often sufficient. If a hand cream “burns” when applied, change to a different cream. Many hand creams contain lactic acid, which may cause some burning of the skin, especially if the skin is cracked. In more severe cases, where the skin is raw or cracked, a mild cortisone cream is often of help.For severe cases, where there are numerous fissures, a cortisone cream combined with an antibiotic will be prescribed. This will treat any fissures that are infected. It is important to note that if fissures are present, for example, over the knuckles, then any movement of the finger is going to open and close that fissure. Such a fissure will not heal. In such cases, simple “splinting” of the skin with a plain “plaster” bandage for about four or five days will often close that fissure.I am a 54-year-old woman with Type 2 diabetes and high cholesterol, both of which are under control. Aside from this I am in good health, slim and exercise regularly. I recently developed an extremely itchy rash on my chest, back, legs and arms. But neither my family doctor nor specialists have been able to solve the problem. Tests were normal. The allergy doctor said it is not an allergy but something “viral” or “environmental,” but she tested me for food allergies and found none. My dermatologist gave me Dermovate cream to put on for a week, but there is no improvement. My family doctor put me on a course of prednisone steroids, hoping to help my condition. Heat definitely exacerbates the problem, so we keep the air conditioning on when it’s hot. I have sleepless nights because I am so itchy, and the only thing that helps for a very limited period is a cool shower. What could the problem be? T.T., via e-mail Prof. Meir Shalit, head of the allergy and immunology unit at Hadassah University Medical Center in Jerusalem’s Ein Kerem, comments: You should wait and see the effect of the prednisone. It seems to me to be a dermatological problem. You may want to go to another dermatologist for a second opinion and/or for a skin biopsy.Rx for Readers welcomes queries from readers about medical problems. Experts will answer those we find most interesting. Write Rx for Readers, The Jerusalem Post, POB 81, Jerusalem 91000, fax your question to Judy Siegel-Itzkovich at (02) 538-9527, or e-mail it to firstname.lastname@example.org, giving your initials, age and place of residence.