Factors associated with palmoplantar or plantar pompholyx: a case-control study

BACKGROUND: Disydrosis or pompholyx is a chronic and recurrent form of dermatosis that poses a number of therapeutic issues. The etiopathology of the condition is unclear. The aim of this study was to identify factors associated with the palmoplantar and plantar dysidrosis. PATIENTS AND METHODS: This was a prospective case-control study conducted between June 2001 and February 2004 at the University Hospital of Lome (Togo). Each case (palmoplantar or plantar pompholyx) was matched for age (+/- 5 years) and sex with two controls. Examination for tinea pedis was performed in all participants (patients and controls) but mycologic culture alone was done in patients with interdigital-plantar intertrigo. RESULTS: One hundred patients with pompholyx were matched with 200 controls. Mean age was 32.8 +/- 14.8 years in the patient group and 31.4 +/- 14.8 years in the control group. For univariate analysis, the main factors associated with pompholyx were: personal atopy (OR = 12.6; CI95%: 6.4 - 25.1) and familial atopy (OR = 5.8; CI95%: 3.2 - 10.5); history of eczema (OR = 5.4; CI95%: 2.6 - 11.4); hyperhidrosis (OR=4.5; CI 95%: 5.5 - 40.7), sport (OR = 8.8; CI 95%: 3.9 - 20.8); tinea pedis (OR = 15.6; CI 95%: 7.5 - 32.9). In multivariate analysis, atopy (OR = 10.5; CI95%: 8.4 - 20.8) and tinea pedis (OR = 18; CI95%: 10.5 - 25.2) were the only factors associated with pompholyx. Trichophyton rubrum was the most common etiology of tinea pedis in both patients and controls.DISCUSSION: The results of this study show atopy and tinea pedis as factors statistically associated with palmoplantar or plantar pompholyx. However, only cohort studies can determine the precise causal relationship between tinea pedis and pompholyx.