Etiologic and causative factors in perianal dermatitis: results of a prospective study in 126 patients.

Background: Perianal dermatitis is probably the most common cutaneous disorder of the genitoanal area. Studies on the epidemiology of causative factors are rare.
Methods: Over a 4-year period we prospectively studied 126 patients with a presumptive diagnosis of anal eczema. The diagnostic algorithm comprised medical history, inspection, microbiology, laboratory chemistry, patch tests, proctoscopy, and biopsy if appropriate.
Results: The age range was 7-82 years and the majority of patients were male (57.1%). Periods of anal symptomatology ranged from 6 days to 120 months and most of the patients (51.6%) had complaints for more than 12 months. The clinical diagnosis in 68 patients (54%) was: intertrigo/candidiasis (42.9%), atopic dermatitis (6.3%), pruritus ani (5.6%), psoriasis (3.2%), skin atrophy from steroid use (2.4%), lichen sclerosus et atrophicus (n = 2), herpes simplex (n = 1), and condylomata acuminata (n = 1). Contact eczema was suspected in 58 patients (46%), but 25 of these (43.1%) showed no contact sensitization.
Conclusion: The majority of patients with symptoms of anal eczema suffer from intertrigo/candidiasis, and relevant, causative contact sensitization may be found in only some of them. Patch-testing is a valuable investigative tool only when the patients' own products are included in the test series. Most patients suffer from their perianal complaints for more than 12 months, therefore diligent evaluation is warranted.