Diagnosis and skin tests for allergies
Allergy is a hypersensitivity reaction to any substance that comes into body weather through the airways, food or through the skin. Symptoms can vary from general (systemic) to localized to an organ or organ system through which the allergen entered the body (skin, mucous membranes, gastrointestinal or respiratory system). History of the development of symptoms after ingestion of allergens in the body or after contact with a potential allergen is of critical importance in recognition and prevention of allergic diseases. Many patients are exposed to different allergens in their everyday life so it is important to pay attention to the details of the working environment and eating habits.
Prick test is the most performed test in case of food and inhalation allergies (pollen, dust mites, feathers, animal hair). Prick or skin prick test is used for testing early hypersensitivity mediated immune response by confirming presence of IgE (immunoglobulin E) in the skin responsive to a particular allergen. Testing is performed in two phases: 1) positive (histamine) and negative control (buffer), which is read after 10 minutes and 2) applying droplets of desired concentrated allergen on the inside of the forearm pierced then with a plastic lancet. The reaction is observed after 20 minutes. If there is a positive reaction at the injection site a slight swelling wheal) will appear.
Patch test on contact allergens standard test for the detection of contact allergy or delayed hypersensitivity reaction to contact allergens. Test is performed by applying test patches usually on the back and test readings are performed after 48 and 72 hours. In case of a positive reaction to an allergen in a place of contact edema or redness with tiny bubbles filled with clear liquid occurs.
Fungi diagnosis and treatment
Fungi diagnosis mainly involves native microscopic examination of planed skin and / or chipped nails. If fungal infection is suspected species of fungi can be identified with results finished in over a fortnight. It’s important to discontinue any antifungal (topical) treatment for at least 3 to 10 days before swab or skin scrapings.
Wood’s lamp
Wood’s lamp is a device that emits ultraviolet light (365 nm Daily Important length), which is often used in dermatology to help with diagnosis of certain skin conditions. Testing is performed in a darkened room, where light from the Wood’s lamp is directed directly onto the affected skin in order to see whether some parts of the skin fluorescence. Normal skin does not fluorescence. If there is a certain type of bacteria, fungi, or there is a change in pigmentation, Wood’s light examination will help confirm the suspected diagnosis. This technique can help in diagnosis of skin condition such as fungal infection, erythrasma, porphyria cutanea tarda, vitiligo and hypopigmented and depigmented changes in infants when the skin has not been exposed to UV rays.
