CANDIDAL BALANO-POSTHITIS - A STUDY OF DIAGNOSTIC METHODS

Objectives-To compare microscopy with culture for diagnosing candidal balanoposthitis and to document which diagnostic methods are used in g enitourinary medicine clinics in Great Britain. Design-(a) Penile mate rial for microscopy and fungal culture were obtained from men with bal ano-posthitis. A ''plain-slide'' method of collecting material for mic roscopy was compared with a novel ''adhesive-tape'' method of sampling . (b) Questionnaires were sent to all genitourinary medicine clinics i n Great Britain. Setting-The Department of Genitourinary Medicine, Add enbrooke's Hospital, Cambridge, England. Main outcome measures-The sen sitivity and specificity of microscopy using culture as the ''gold sta ndard'' for diagnosis. Results-Candida was isolated from 35% of 450 me n with balano-posthitis attending the clinic over a three year period. The sensitivity of microscopy compared with culture was 12% ''plain-s lide'' method of material collection) and 65% (''adhesive-tape'' metho d) (p < 0.0001). The respective specificities were 95% and 81%. The po sitive predictive values for the two methods of material collection we re 50% (''plain-slide'' method) and 75% (''adhesive-tape'' method). Th e respective negative predictive values were 71% and 72%. 60% of 250 g enitourinary medicine clinics returned questionnaires. 13% routinely d iagnosed candidal balano-posthitis by appearance only and 34% sometime s relied only on clinical appearance. Culture was used by 78% and micr oscopy by 69% of clinics. Material for microscopy was most commonly co llected by using a cotton-wool tipped swab and the Gram stain was the favoured method for microscopy. Conclusion-Candida is a common cause o f balano-posthitis. Diagnosis by microscopy has a low sensitivity and varies with the method used for collecting material. Although up to on e third of genitourinary medicine clinics may rely solely on clinical appearance for diagnosis most continue to use microscopy and culture.