Is psoriasis contagious?
No, psoriasis is not contagious. This is a common misconception because of the visible nature of lesions on exposed skin, which appears very red and inflamed. In reality, psoriasis does not have a tendency to become infected, perhaps because of the rapid turnover of the cells in a psoriatic plaque. However, if the psoriasis plaques are itchy and the patient scratches or picks at the lesions to remove scales, open, cracked or raw skin areas can develop and may get infected.
Since psoriasis is not contagious, how
does it spread?
Psoriasis is not contagious and it is not spread by skin-to skin contact. We do not understand all of the reasons why psoriasis appears in certain skin sites. Lesions often develop in areas of pressure such as on the elbows and knees, or on the knuckles of the hands. It can, however, appear anywhere on the body including the scalp, palms and soles, skin folds and genital areas. Trigger factors including skin injury—friction or irritation can result in the appearance of psoriasis on a certain skin site. This is called the Koebner phenomenon. Infection can also make it worse. A type of widespread psoriasis appearing as small droplike plaques all over the body may be triggered by a streptococcal sore throat (strep throat).