Guttate Psoriasis: A Rare Skin Disease Triggered by Strep Throat

While most people have heard of psoriasis, very few know anything about a rare form of psoriasis called guttate psoriasis. The actual term guttate comes from the Latin term gutta that means droplet. Guttate psoriasis got its name because the rash that forms looks like little red, raised droplets of water. Most types of psoriasis form scale-like lesions called plaque. This is because the skin cells divide too rapidly and raise up on the skin surface, then flake off. But guttate psoriasis is composed of these small pink or red bumps and rarely have any noticeable plaque on them or associated with them. The bumps are usually itchy, but not always.

One strange part of guttate psoriasis is that it is generally triggered by a strep throat infection (streptococcal bacteria). The rash does not appear right away, but can take anywhere from 2 to 3 weeks to appear. This may make it hard to diagnose unless the patient remembers that they had strep throat several weeks prior. When the rash does appear, it usually starts on the legs or arms and quickly spreads to the abdomen, chest, back and sometimes the scalp and face. In most cases, the guttate psoriasis will slowly disappear on its own, but this can take several months, or even longer in some people. Mild flares can go away faster than the more severe cases.

Because psoriasis can be hereditary, a person may not know they have inherited psoriasis until they break out after strep throat. Statistics say that less than 2% of people who have psoriasis will get the guttate variety, which makes it very rare. Gender does not seem to apply in cases of guttate psoriasis, but age seems to be a fact. Younger people are more likely to get it than adults over 30 years of age. Also, a person who already has plaque psoriasis could get a flare of guttate psoriasis. Strep throat is not the only infection that can trigger guttate psoriasis. The common cold or chicken pox can be a trigger as well.

The reason someone gets a flare up of guttate psoriasis is not well known, but it is believed to be an immune response to a past infection because patients could have a larger amount of white blood cell antigens. Interestingly, the antigen C gene on the leukocyte (white blood cell) is expressed only in cases of psoriasis. This means that the body tries to fight the streptococcal infection by producing a large amount of antibodies and this triggers the guttate reaction.

A doctor cannot do too much except prescribe antibiotics for the strep infection and a steroid or anti-itch cream to try to ease the rash, but mostly a person with guttate psoriasis will have to wait until the flare eases on its own.