Confluent and Reticulated Papillomatosis
The areas of hyperpigmentation shown here on the trunk of a 15-year-old girl appeared 2 years earlier as 1- to 2-mm hyperpigmented papules with either flat or verrucous surfaces. The papules gradually enlarged and coalesced into confluent plaques with reticulated borders. Examination revealed diffusely distributed lesions over the neck and upper abdomen with a velvety, hyperkeratotic texture. The patient denied pain and pruritus. Previous application of topical ketoconazole had been ineffective.
These skin changes are characteristic of confluent and reticulated papillomatosis (Gougerot-Carteaud syndrome), which usually develops in postpubescent teenagers. Males and females are equally affected; evidence of a racial predilection is conflicting.1 Although this condition is very rare (with only 39 cases reported in the past 30 years2), it is probably underdiagnosed and/or underreported because of its benign nature.
Typical distributions may include the neck, back, axillae, breasts, and upper abdomen.1 Biopsy, which may be performed to confirm the diagnosis, reveals hyperkeratosis, papillomatosis, increased melanin deposition, and acanthotic projections deep into interpapillomatous valleys.1 However, the lesions may lack hyperpigmentation3 and histological papillomatosis,4 and they may present with a fine scale or associated mild pruritus.1
The differential diagnosis includes more common conditions, such as acanthosis nigricans and tinea versicolor. Acanthosis nigricans seldom presents on the trunk and lacks peripheral reticulation. Tinea versicolor produces a white-to-brown keratinaceous scale that reveals Malassezia in potassium hydroxide preparation; unlike confluent and reticulated papillomatosis, tinea responds to antifungal medication.
Although the cause remains unknown, some theories include faulty keratinization, bacterial infection, reaction to Pityrosporum yeast, and reaction to UV light. More than 80% of patients treated with minocycline or azithromycin respond completely, and 10% to 15% exhibit a partial response; successful treatment confirms the diagnosis.1,2 However, recurrence rates as high as 50% have been reported with the cessation of therapy.1,2 In recurrent cases, repeated antibiotic courses may be used because acquired antibiotic resistance has not been described.
This patient was treated with minocycline, 100 mg twice daily for 6 weeks. This treatment, first described in 1965 by Carteaud,5 has been supplanted by azithromycin, 500 mg 3 times weekly for 3 weeks, because of the latter’s benign adverse-effect profile. Other therapeutic options include topical or systemic retinoids and vitamin D derivatives, such as calcipotriol.1 Untreated confluent and reticulated papillomatosis follows a chronic course of plaque expansion and recession. Over years to decades, individual lesions may stabilize and remain permanently.
REFERENCES:
1. Scheinfeld N. Confluent and reticulated papillomatosis: a review of the literature. Am J Clin Dermatol. 2006;7:305-313.
2. Davis MD, Weenig RH, Camilleri MJ. 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. Br J Dermatol. 2006;154:287-293.
3. Treat JR, Barak OG, James WD. Nonpigmenting confluent and reticulated papillomatosis. Pediatr Dermatol. 2006;23:497-499.
4. Mutasim DF. Confluent and reticulated papillomatosis without papillomatosis. J Am Acad Dermatol. 2003;49:1182-1184.
5. Carteaud A. A case of Gougerot and Carteaud’s confluent and reticulated papulous papillomatosis, completely cleared up by antibiotics [in French]. Bull Soc Fr Dermatol Syphiligr. 1965;72:396-397.
(Case and photograph courtesy of Andrew M. Goldsweig, MD.)
