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.
Introduction. Pityriasis versicolor, sometimes called tinea versicolor, is a common condition that causes small patches of skin to become scaly and discoloured. The patches may be darker or lighter than your normal skin colour, or may be red or pink.They tend to develop gradually and may join up to form larger patches over time.ityriasis versicolor, sometimes called tinea versicolor, is a common condition that causes small patches of skin to become scaly and discoloured. The patches may be darker or lighter than your normal skin colour, or may be red or pink. They tend to develop gradually and may join up to form larger patches over time.