Dr Shah Hussain
Q: My son has had eczema since he was born 2 years ago. My doctor has suggested 'patch' testing. What does this involve and where can I get it done. Sadia, Lahore
A: Some general physicians have a special interest in allergy testing and your doctor could refer you to one of those doctors if he or she was unable to do the testing for you. Alternatively your doctor could refer you to see a specialist for further testing. The patch test involves applying several common allergens to the skin. These are usually applied in batches to the skin on the child's back. The skin is then inspected within a few days to detect if any reaction has occurred on the child's skin. If the child is allergic to any of the allergens, an area of inflammation develops at the point where the particular allergen was applied. Once the allergen has been identified it may then be possible to avoid the child being exposed to that agent in the future, which should help to prevent further relapses of eczema. The theory behind patch testing is very sound but in practice it is often discovered that the child has multiple allergies to very common ubiquitous agents that cannot be easily avoided.
Q: I am 24 weeks pregnant and have developed this intense itching from my wrist to shoulder and across my upper back. My doctor has advised me to take an antihistamine to relieve the itch. Will this condition ever go away? It is seriously affecting my everyday life. Please help. Beena Ali
A: Itch is a very common symptomcity during pregnancy and in many cases it can persist until delivery takes place. Assuming that you don't have a rash since you did not mention in your question. If a rash were present then that would raise the possibility of a dermatological cause for the itch. However, it is worth mentioning in passing that many dermatological conditions, including eczema, actually improve during pregnancy. Since you have only recently developed this itch and you are now coming close to the third trimester of pregnancy it might be worthwhile having a liver function test performed to measure the level of bile in your blood. There is a condition that occurs during pregnancy that is known as cholestasis, which means that the level of bile acid in the blood increases due to the effect of the changed oestrogen levels. This increase in bile can cause intense itch. There is a specific treatment available for this condition that can be safely taken for the remainder of the pregnancy. It is probably a bit early for cholestasis to occur but given the intense level of the itch and the fact that it is of recent origin it might be worth testing. If the bile levels are normal then you have to try to manage the itch as best as you can. Emollient bath additives may help in addition to the antihistamine that you are already taking. Antihistamines can particularly be helpful at night when their mild sedative effects can assist sleeping, which can be a great problem for many women suffering from severe itch during pregnancy. Some women find that talcum powder and moisturising creams also give relief.