Confluent and Reticulated Papillomatosis of Gougerot and Carteaud: A Case Report and Review of the Literature

Confluent and reticulated papillomatosis (CARP) of Gougerot and Carteaud is a rare chronic disease with exacerbation and remissions typically affecting young people. Classic clinical characteristics include asymptomatic scaly hyperpigmented macules, patches, and papules in the trunk's confluent and reticular pattern. A 12-year-old girl, otherwise healthy, presented with itchy, persistent skin lesions all over her body for one year. Skin examination revealed generalized scaly brownish patches, thin papules, and plaques all over her body, including her face, neck, middle of the chest, abdomen, back, upper extremities, elbows, lower extremities, and knees. Wood's lamp examination of her skin lesions was unrevealing. Skin biopsy showed papillomatosis, hyperkeratosis, acanthosis, and hypergranulosis. The dermis showed perivascular inflammatory cellular infiltrate. Based on the above clinicopathological findings, the patient was diagnosed with CARP. In our case, a generalized form was reported. CARP is diagnosed based on clinical and histopathological features. Oral antibiotics are the cornerstone of treatment. Our patient responded well to oral minocycline 85 mg one tablet daily, tacrolimus 0.1% ointment twice daily, and selenium sulfide shampoo twice weekly for two months. The classic clinical characteristics of CARP include asymptomatic scaly hyperpigmented macules, patches, and papules in a confluent and reticular pattern on the trunk. A generalized form, as in our case, has been reported. CARP is diagnosed based on clinical and histopathological features. Oral antibiotics are the cornerstone of treatment.

Acanthosis Nigricans: An Updated Review

BACKGROUND

Early recognition of acanthosis nigricans is important because acanthosis nigricans can be a cutaneous manifestation of a variety of systemic disorders and, rarely, as a sign of internal malignancy.

OBJECTIVE

The purpose of this article is to familiarize pediatricians with the clinical manifestations, evaluation, diagnosis, and management of acanthosis nigricans.

METHODS

A search was conducted in November 2021in PubMed Clinical Queries using the key term "acanthosis nigricans". The search strategy included all clinical trials, observational studies, and reviews published within the past 10 years. Only papers published in the English literature were included in this review. The information retrieved from the above search was used in the compilation of the present article.

RESULTS

Acanthosis nigricans is characterized by symmetric, hyperpigmented, and velvety plaques with ill-defined borders, typically involving intertriginous areas. Obesity is the most common cause of acanthosis nigricans which is increasingly observed in obese children and adolescents and can serve as a cutaneous marker of insulin resistance. Early recognition of acanthosis nigricans is important because acanthosis nigricans can also be a cutaneous manifestation of a variety of systemic disorders and, rarely, as a sign of internal malignancy. This may consist of weight reduction, discontinuation of causative drugs, treatment of underlying endocrinopathy, or treatment of an underlying malignancy. For patients with isolated acanthosis nigricans and for those whose underlying cause is not amenable to treatment, treatment of the lesion may be considered for cosmetic reasons. Topical retinoids, vitamin D analogs, chemical peels, and other keratolytics are often used for the treatment of localized lesions. Seldom, systemic therapy such as oral retinoids may be considered for extensive or generalized acanthosis nigricans and acanthosis nigricans unresponsive to topical therapy. Other uncommon treatment modalities include dermabrasion, laser therapy, and surgical removal.

CONCLUSION

Although acanthosis nigricans is treatable, a complete cure is difficult to achieve. The underlying cause should be treated, if possible, to resolve and prevent the recurrence of acanthosis nigricans. The diagnosis is mainly clinical, based on the characteristic appearance (symmetrically distributed, hyperpigmented, velvety, papillomatous, hyperkeratotic plaques with ill-defined borders) and the typical sites (intertriginous areas, flexural area, and skin folds) of the lesions. The diagnosis might be difficult for lesions that have atypical morphology or are in an unusual location. Clinicians should be familiar with the clinical signs, evaluation, diagnosis, and therapy of acanthosis nigricans because of the link between it and underlying diseases.

Resolution of confluent and reticulated papillomatosis after bariatric surgery

Confluent and reticulated papillomatosis (CARP), a rare dermatologic disorder characterized by hyperpigmented papules that subsequently develop into plaques with reticulated margins, is frequently confused with acanthosis nigricans. The aetiology and pathogenesis of CARP is not yet fully understood, but it is often present in individuals with obesity and PCOS. This case report describes an African American adolescent female with obesity with a rash diagnosed as CARP after unsuccessful treatment with antifungals and corticosteroids. Her dermatosis proved recalcitrant to antibiotics and metformin but started to resolve immediately after bariatric surgery. This case report supports insulin resistance as a contributor to CARP's pathogenesis and as well as its association with obesity. Clinically significant weight reduction should be considered in the management of this challenging skin condition.