Confluent and reticulate papillomatosis (Gougerot-Carteaud syndrome): a minocycline-responsive dermatosis without evidence for yeast in pathogenesis. A study of 39 patients and a proposal of diagnostic criteria.

Background: Confluent and reticulate papillomatosis (CRP) (Gougerot-Carteaud syndrome) is a disorder that has been characterized in only small cohorts of patients.

Objectives: Better to characterize the clinical and pathological findings of the disorder.

Methods: We retrospectively reviewed the clinical presentation, response to treatment and histological findings of patients presenting to Mayo Clinic (Rochester, MN, U.S.A.) with CRP.

Results: The disorder was diagnosed in 39 patients between 1972 and 2003. Mean age at onset of the skin eruption was 15 years (range 8-32); 21 patients (54%) were male; most were white; most (33) presented for reasons of cosmesis; and eight described the rash as mildly pruritic. At presentation, the skin eruption had been present for a mean of 3.1 years (range 3 months-20 years) and had been recalcitrant to treatment, including antifungal treatment. Typical objective findings were scaling brown macules and patches and velvety papules and plaques, reticulated and papillomatous at least in part, involving the upper trunk, axillae and neck. The most frequent initial diagnostic impressions were tinea versicolor, acanthosis nigricans and CRP. Scales in 32 cases were examined with potassium hydroxide: eight (25%) showed hyphae, and 24 (75%) did not. Skin biopsy specimens from 21 patients showed variable degrees of hyperkeratosis, acanthosis and papillomatosis. Minocycline was prescribed for 22 patients, of whom 14 of 18 (78%) had complete clearing of the skin eruption and four (22%) a partial response. The skin eruptions recurred after stopping treatment in six patients.

Conclusions: CRP occurs predominantly in young adults and teenagers, with cosmetically displeasing brown scaling patches and plaques affecting the neck, upper trunk and axillae. Frequently, the diagnosis is delayed and the disorder not recognized by physicians, including dermatologists. Clinically, the eruption is most often confused with tinea versicolor. Potassium hydroxide staining of the scale is negative in the majority of cases, implying that fungi are not involved in the pathogenesis of this condition, as has been previously proposed. It is important to recognize this disorder, because minocycline therapy is highly effective in most patients. Criteria for the diagnosis are proposed.