Guttate Psoriasis

Guttate Psoriasis Overview

Guttate psoriasis is a type of psoriasis that looks like small, salmon-pink drops on the skin. The word guttate is derived from the Latin word gutta, meaning drop. Usually there is a fine scale on the droplike lesion that is much finer than the scales in plaque psoriasis, which is the most common type of psoriasis.

Guttate psoriasis. Red droplike lesions are found on the skin.
Image courtesy of Hon Pak, MD.

Guttate psoriasis is not contagious and may be inherited. Guttate psoriasis usually occurs on the trunk, arms, or legs. However, it may cover a large portion of the body.

The trigger to the disease is usually a streptococcal (bacterial) infection. The eruption of the lesions on the skin usually happens about 2-3 weeks after the person has strep throat. The outbreak can go away and not reoccur. Outbreaks may also go away and come back, particularly if the person is a strep carrier (always carries streptococcal bacteria in his respiratory system).

The sudden appearance of an outbreak may be the first psoriasis outbreak for some people. Alternatively, a person who has had plaque psoriasis for a long time may suddenly have an episode of guttate psoriasis. This type of psoriasis can also be chronic and can be triggered by infections other than those from streptococcal bacteria. For example, the chicken pox or colds can trigger the psoriasis.

Who gets guttate psoriasis?

The guttate form of psoriasis is relatively uncommon. Fewer than 2% of those with psoriasis have the guttate type. Guttate psoriasis is more common in children and adults younger than 30 years. Boys and girls are equally affected.

Guttate Psoriasis Causes

An outbreak of guttate psoriasis may be an immune reaction that is triggered by a previous streptococcal infection or some other type of infection. The immune system makes white blood cells that protect the body from infection. In psoriasis, the T cells (a type of white blood cell) abnormally trigger inflammation in the skin and the production of excess skin cells.

Guttate psoriasis may be inherited. Those with a family history of psoriasis have an increased chance of having the disease. Some people carry genes that make them more likely to develop psoriasis.

People with guttate psoriasis may have a significantly higher number of human leukocyte antigens BW17, B13, or CW6 than others. Psoriasis is the only disease associated with the human leukocyte antigen C gene expression.

Antigens are proteins on the surface of bacteria, viruses, or material foreign to the body. The body's immune system recognizes the type of antigen present and makes an antibody to destroy the bacteria, virus, or foreign material.

When the body has a streptococcal infection, it produces antibodies to streptolysin-O that is on the bacterial cell. People with an excess of human leukocyte antigen B13 may not be able to produce enough antibodies to the streptolysin-O, which may be associated with the high rate of guttate psoriasis in these individuals.

Factors that may trigger guttate psoriasis include the following: 

• Streptococcal infection: As many as 80% of people with guttate psoriasis have a streptococcal infection, usually in the form of tonsillopharyngitis, before the outbreak. Even though the connection between these infections and the outbreaks has been known for over 50 years, the exact mechanism by which the infection triggers the lesions is unknown.

   

• Viral infections, such as chicken pox, rubella, and roseola, may also trigger outbreaks in children.