IgA deficiency, a selective lack of immunoglobulin A (IgA). The most common type of immunoglobulin deficiency, it occurs in about 1 in 400 individuals. IgA is a major antibody in the saliva and in the mucous membranes of the intestines and the bronchi. It protects against bacterial and viral infections.gA deficiency, a selective lack of immunoglobulin A (IgA). The most common type of immunoglobulin deficiency, it occurs in about 1 in 400 individuals. IgA is a major antibody in the saliva and in the mucous membranes of the intestines and the bronchi. It protects against bacterial and viral infections.
Pityriasis rubra pilaris (PRP) refers to a group of skin conditions that cause constant inflammation and scaling of the skin. People with PRP have reddish, scaly patches that may occur everywhere on the body, or only on certain areas.
Pityriasis alba is a disorder which is most often seen in children. It is unknown what the causes of the disease are. Pityriasis alba results in scaly patches of skin. When these scaly patches clear up, a pigmented area is left.Eventually this will return back to normal skin colour.he initial patches caused by pityriasis alba are round, oval or irregular in shape and red or pink in colour. They are also usually scaly and are between 0.5 and 2cm wide. In children, these patches are usually found only on the face and in particular the mouth, chin and cheeks.