Causes & Triggers
The cause of psoriasis is not fully understood. Psoriasis lesions occur because the overactive immune system speeds up skin cell growth. Normal skin cells completely grow and shed (fall off) in a month. With psoriasis, skin cells do this in only three or four days. Instead of shedding, the skin cells pile up on the surface of the skin.
Inflammation caused by psoriasis can impact other organs and tissues in the body. People with psoriasis may also experience related health conditions. One in three people with psoriasis may also develop psoriatic arthritis.
Common triggers for guttate psoriasis include:
- Certain medicines, such as antimalarials and beta blockers
- Infections such as the flu, sinus infections, or upper respiratory infections
- Streptococcal infection
- Tonsillitis (inflammation of the tonsils)
- Injury to the skin
- Stress
Learn more about triggers and flares by requesting a free Flare Guide and Symptom Tracker.
Diagnosis
A health care provider will take several factors into consideration when making a diagnosis for psoriasis, including:
- The appearance of the skin. Guttate psoriasis appears as many small, round, and scaly spots.
- The location of psoriasis. There are areas on the body that are more common for psoriasis to appear.
- Itch of the skin. This is a common symptom of psoriasis.
- A skin biopsy (the removal of a small piece of skin to be looked at under a microscope) may be needed if the diagnosis is not clear from visual inspection. The biopsy may also be done to determine if it is psoriasis or another skin condition. However, most often, psoriasis can be identified by examining the skin and does not usually require a skin biopsy.
Guttate psoriasis may be mistaken for other conditions, including pityriasis rosea, pityriasis lichenoides chronica, tinea versicolor, and lichen planus. [4] A dermatologist can usually make the diagnosis based on the appearance of the skin and medical history.
