Aggravation of psoriasis by infections: a constitutional trait or a variable expression?

Focal infections are a well known triggering factor in patients with psoriasis. A question which remains to be answered is whether relapsing of psoriasis after infections is a constitutional trait of a restricted population or whether it is a feature of all patients in some phase of their disease. A questionnaire was mailed to patients with psoriasis comprising general questions, psoriasis related questions and questions on the relationship between focal infections and aggravation of psoriasis. The questionnaire was mailed to 126 patients and 45 questionnaires which were returned, were evaluable. From the 45 questionnaires the following preliminary conclusion can be drawn. Aggravation of psoriasis following infections appeared to be a consistent trait throughout the duration of psoriasis in 18% of patients as opposed to 71% of the patients who did not experience this association at all and 11% who experienced the association sometimes. Patients who experienced aggravation of psoriasis by infections as a consistent feature have an age of onset 9 years earlier as opposed to patients without this association and express guttate psoriasis in the vast majority as first manifestation at initiation of psoriasis. These patients had an average of 4.6 relapses per year in contrast to 1.1 per year in the patients without an association between infection and aggravation of psoriasis. In these patients infections proved to be responsible for 67% of the exacerbations. Stress was indicated in this subpopulation as a triggering factor as well in 88% of the patients. Although this conclusion only can be very preliminary based on the small group of patients, we may conclude that patients with a strong association between aggravation of psoriasis and infections belong to a restricted population of patients tending to an unstable course of the disease.