Читать книгу Eczema: Your essential guide - Regina Malan - Страница 10

There is no single, indisputable test that doctors can perform to determine whether a patient has eczema. Diagnosis is done on the basis of:

•A thorough examination. Even if your only complaint when visiting the doctor is a rash on your hands, he or she may examine your entire body for signs of eczema.

•Symptoms. Taking into consideration all the symptoms listed earlier, especially the rash and accompanying itch. Itching is a significant indication of eczema.

•Family history. A complete family history to determine the tendency towards eczema, asthma and allergic rhinitis.

•An escalation in IgE levels in the blood. IgE (immunoglobulin) is a type of protein produced by the immune system. It is an antibody that only occurs in mammals and it protects the body by attacking the protein component of foreign substances. Everyone’s blood contains IgE, but some eczema sufferers show increased levels in their blood. During an allergic reaction the IgE antibodies release chemicals that damage the surrounding tissue. A blood test will be performed to determine IgE levels.

•Allergy tests. Since many people suffering from eczema also show allergies, the doctor may perform allergy tests to determine possible irritants and triggers. Especially children with eczema will most probably be tested for allergies.

•Food allergies. They can be determined by means of skin prick testing and skin patch testing. A negative reaction may result from skin prick testing, but allergies may be present in spite of the negative results. Skin patch testing can then be an effective testing method.

•Blood tests. These may also be considered, mainly to eliminate other conditions and to test IgE levels, as described above. IgE antibodies play a role in allergic reactions to food. Blood tests are also used to measure eosinophil levels. Eosinophils are antibodies that are also involved in allergic reactions, especially allergies to medicines. Raised eosinophil levels in the blood or in tissue where medicines are concentrated, can potentially cause an allergic reaction.

A study published in the Indian Journal of Dermatology, Venereology and Leprology found that eosinophil and IgE counts are significantly higher in patients with atopic dermatitis and that these raised levels also have an effect on the severity of the condition.3

A skin biopsy is a procedure in which a small sample of skin tissue is taken and sent to a laboratory to be examined under a microscope

•Skin biopsies. Dr Johan van Wyk, a Johannesburg dermatologist, says he often makes use of skin biopsies for an accurate diagnosis. According to him, a spot of eczema may sometimes show similarities with skin cancer. It is therefore essential to get clarity on the condition. Some cancers may also be accompanied by lots of itching, and the use of steroids – commonly prescribed for eczema – will worsen the cancer situation. A skin biopsy is helpful in arriving at a correct diagnosis.

•Skin swabs. A skin swab of the rash may be taken with a cotton bud and sent to a laboratory. Skin swabs are not especially functional in diagnosing eczema, but are used to determine the type of skin infection present in order to prescribe the right medication.