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 rosea is a skin disease of uncertain origin characterized by lesions bordered by collar-like areas that tend to. peel off in tiny scales. Pityriasis comes from the Greek word for bran, pityron, because the flakes of skin shed from the lesions resemble small pieces of wheat bran.ityriasis rosea is a common benign skin disease, or exanthem, that was first described by a French physician named Camille Gibert in 1860. It is classified as a papulosquamous disorder, which means that its lesions are marked by small raised areas (papules) as well as scaly areas.