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.
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.
Guttate psoriasis may also 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.
Guttate Psoriasis Symptoms
- Small, salmon-pink (or red) drops usually appear suddenly on the skin two to three weeks after a streptococcal infection, such as strep throat or tonsillitis.
- The drop-like lesions usually itch.
- The outbreak usually starts on the trunk, arms, or legs and sometimes spreads to the face, ears, or scalp. The palms and the bottoms of the feet are usually not affected.
- Nail changes, such as pits and ridges, which are characteristic of chronic psoriasis, may not occur.
When to Seek Medical Care
You may want to see your doctor or health care practitioner if you have a sudden eruption of small red drop-like lesions of guttate psoriasis. This form of psoriasis is usually a mild inconvenience to most people. Most of the time, the lesions last several weeks to a few months. Other times, the guttate eruption can develop into chronic plaque psoriasis. Scarring is not a problem.
The doctor can prescribe treatments that help relieve itching. This type of psoriasis usually "runs its course" and goes away without treatment in a few weeks.