Objectives: To characterize patients with anogenital dermatitis referred for patch testing by the North American Contact Dermatitis Group, to identify common allergens, and to explore sex associations. Design: Retrospective, cross-sectional analysis of the North American Contact Dermatitis Group database, 1994-2004. Patients: Five hundred seventy-five patients with anogenital signs or symptoms were referred for patch testing; 347 had anogenital disease only. Main Outcome Measure: Currently relevant allergic patch test reaction in patients with anogenital signs or symptoms. Results: Sex percentages and mean age were not significantly different in patients with anogenital involvement only compared with those without anogenital involvement. In patients with anogenital involvement only, a final diagnosis of "other dermatoses" was statistically significantly more common in female patients compared with male patients (n=347; relative risk, 1.99; 95% confidence interval, 1.37-2.91), but the diagnosis of allergic contact dermatitis was not associated with sex. Specific allergens that were statistically significantly more common in patients with anogenital involvement included cinnamal (or cinnamic aldehyde), dibucaine, benzocaine, hydrocortisone-17-butyrate, and budesonide (all P<.005). Those that were statistically significantly less frequent included quaternium-15, cobalt chloride, formaldehyde, p-phenylenediamine, and thiuram mix (all P<.04). Seventy-three patients had anogenital allergic contact dermatitis, defined as anogenital involvement only, allergic contact dermatitis as the only diagnosis, and at least 1 positive reaction of current clinical relevance. In that subgroup, the most common allergen sources were cosmetics, medications, and corticosteroids. Conclusion: In patients in the North American Contact Dermatitis Group with anogenital involvement only, male and female patients were equally likely to have allergic contact dermatitis but female patients were more likely to have other dermatoses. Common allergens and sources consisted of those likely to have contact with the anogenital area.