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 rash that can occur at any age but is most common from age 10 to 35 years and can last from several weeks to several months. The condition often begins as a large single pink patch on the chest or back. This patch may be scaly and is called a âheraldâ or âmotherâ patch.