Q: My son is 2 years old. As per the doctors, his skin is allergic to insect bites. He has this problem since birth. Wherever there is an insect bite, the area around it becomes reddish and after 2 days, it forms a lump and water comes out of it. After 2 weeks the place dries up, leaving a black spot on the skin. What is the reason behind this? What tests need to be done for the same? What is the treatment and whom should I consult? Will he be facing this throughout his life?

A:This type of large and/or persistent insect bite reaction is a nuisance but not dangerous. Insect repellents and physical protection, e.g. nets, may reduce the number of bites, but preventing scratching is important too, once a bite has occurred. Some hydrocortisone cream, 1%, applied to the bite as soon as you notice it, and also soothing lotions like calamine can help. Taking an antihistamine such as chlorphenamine in the appropriate paediatric dose will relieve the itching and reduce the likelihood of scratching. In extreme cases, a single dose of steroid by mouth, such as soluble prednisolone, will generally reduce the size and duration of bite reactions, but should not be taken for more than a few days at most. Unfortunately, some individuals seem to be more attractive than others to biting insects. Some allergies do seem to fade as patients get older, and adults may be better at avoiding bites than children. I don't think any tests are likely to be helpful, and unlike generalised insect sting reactions, these local bite reactions are often not insect-specific, i.e. can occur after gnat, mosquito, horsefly, flea and bedbug bites. Desensitisation is not an option.