What's Your Diagnosis?

Skin Lesions Erupt Across a Teenager’s Upper Back

Alexander K. C. Leung, MD—Series Editor, and Benjamin Barankin, MD

A 17-year-old obese Caucasian female presented with an asymptomatic, brownish eruption on the upper back of approximately 1 year’s duration. The lesions started off as small brownish macules that slowly increased in size and coalesced to form patches with a reticulated pattern over time.

She was in good health and not on any medication. There was no family history of similar skin lesions. 

Brownish Eruption

Physical examination revealed multiple, well-demarcated, brownish, confluent and reticulated macules and patches localized to the upper back. Her height was 168 cm, weight 92 kg, and body mass index 32.6 kg/m2 (normal value <25 kg/m2). The rest of the physical examination was normal.

What’s your diagnosis? 

(Answer and discussion on next page) 

Answer: Confluent and reticulated papillomatosis

Confluent and reticulated papillomatosis—also known as confluent and reticulated papillomatosis of Gougerot and Carteaud, Gougerot and Carteaud papillomatosis, and Gougerot and Carteaud syndrome—is an acquired ichthyosiform dermatosis characterized by persistent dark, scaly macules and patches; they tend to be confluent in the center, reticulated at the periphery, and localized predominately on the trunk.1

Confluent and reticulated papillomatosis

The disorder was first described in 1927 by Henri Gougerot and Alexandre Carteaud under thename “papillomatose pigmentée innominée” and later renamed it as “papillomatose pigmentée confluente et réticulée innominée.”2,3 The condition now bears their names.  


Confluent and reticulated papillomatosis is an uncommon condition; the exact prevalence of it is not known. Typically, the condition begins in the late teens or young adulthood, with a mean onset age of 15 years.4,5 There is no known predilection for race or ethnicity.6  

The condition is slightly more common in females than males, except in Japan where the reverse is true.7 The majority of cases are sporadic but familial cases have been reported.1


The exact etiopathogenesis is not known. There are several hypotheses about the etiopathogenesis of this condition. Confluent and reticulated papillomatosis may result from an endocrine disturbance because the condition is more commonly seen in patients with obesity, diabetes mellitus, Cushing’s disease, hirsutism, menstrual irregularities, thyroid disorder, and pituitary disease.7  

The condition may be a disorder of keratinization, as increased transition cell layers and lamellar granules in the stratum granulosum—along   with increased involucrin, keratin 16, and Ki-67 expressions—have been demonstrated in affected patients.8-10 Some authors suggest that the disease is an abnormal host response to Malassezia species or Actinomyces dietzia.1 There may be a genetic predisposition, as evidence has shown a familial occurrence in some cases.1


Histologic examination of a classic lesion shows compact hyperkeratosis, papillomatosis, decreased or absent granular cell layer, focal acanthosis, and increased transition cell layers and lamellar granules in the stratum granulosum.1,8,9 


Initially the lesions present as small, round, erythematous, flat-topped, hyperkeratotic or verrucous papules or macules.5,6 These papules or macules gradually enlarge to 4 to 5 mm and coalesce to form confluent, slightly scaly patches or plaques centrally and a reticular pattern peripherally.5,6  

Over time, the color of the lesions become brown or dull brown.5 In rare cases, the condition can manifest as rippled reticulated erythema, vertically rippled and keratotic plaques, or as atrophic macules with a shiny quality or a surface change resembling cigarette paper.6,10  

Sites of predilection include the neck, interscapular region, intermammary area, and epigastric area.7 Other areas—such as the face, neck, shoulders, axillae, breasts, flanks, lower abdomen, pubic area, and groin—may also be affected.6 The palmoplantar and mucosal areas are usually spared.7 The lesions are usually asymptomatic and occasionally pruritic.10 There can be a marked xerosis.5


The diagnosis is mainly clinical and can be aided by dermoscopy, which typically shows brownish pigmentation with poorly defined borders covered with white scales (corresponding to basal layer hyperpigmentation, parakeratosis, compact hyperkeratosis) and a pattern of labeled “sulci and gyri” (corresponding to papillomatosis).7  


A potassium hydroxide wet-mount examination of skin scrapings can be performed to rule out a fungal infection. Other laboratory investigations are usually not necessary in an otherwise healthy individual. Skin biopsy is warranted for atypical cases or when the diagnosis is unclear.


The main differential diagnoses are acanthosis nigricans, pseudoacanthosis nigricans, and tinea versicolor. Other differential diagnoses include verrucae plana, terra firma-forme dermatosis, ichthyosis, pigmented contact dermatitis, flat seborrheic keratoses, erythema dyschromicum perstans, dyskeratosis congenita, epidermodysplasia verruciformis, pityriasis rubra pilaris, epidermal nevus, prurigo pigmentosa, amyloidosis, mycosis fungoides, Darier disease, Dowling-Degos disease, and Naegeli-Franceschetti-Jadassohn syndrome.5


Confluent and reticulated papillomatosis does not lead to any systemic disease. It is, however, socially embarrassing because of the cosmetic disfigurement.


Confluent and reticulated papillomatosis tends to run a chronic course, with exacerbations and remissions. The condition rarely spontaneously resolves with time.11 

Underlying causes, such as obesity and endocrine disorders, should be treated if possible. For patients desiring treatment for cosmetic or symptomatic reasons, oral antibiotics such as minocycline, doxycycline, erythromycin, clarithromycin, and azithromycin have been used with success.1  Minocycline, in particular, is the treatment of choice in children over 8 years of age and those with permanent teeth.1,5,10  

Other treatment options include topical antibiotics (mupirocin), topical keratolytics (salicylic acid, urea), topical retinoids (tretinoin, tazarotene), topical antifungals (clotrimazole, miconazole, ketoconazole, selenium sulfide), topical vitamin D3 analogues (calcipotriol or calcipotriene), topical tacrolimus, and oral retinoids (isotretinoin, acitretin).5,12,13


  1. Acikgoz G, Huseynov S, Ozmen I, et al. Confluent and reticulated papillomatosis (Gougerot-Cateaud syndrome) in two brothers. Acta Dermatovenerol Croat.  2014;22(1):57-59.
  2. Gougerot H, Carteaud A. Papillomatose pigmentee innominee. Bull Soc Fr Dermatol Syphilol. 1927;34:719-721.
  3. Gougerot H, Carteaud A. Papillomatose pigmentee confluente et reticulee innominee. Bull Soc Fr Dermatol Syphilol. 1928;35:230-231.
  4. Park YJ, Kang HY, Lee ES, et al. Differentiating confluent and reticulated papillomatosis from acanthosis nigricans. J Cutan Pathol. 2015 Aug 12 [epub ahead of print].
  5. Scheinfeld N. Confluent and reticulated papillomatosis: a review of the literature. Am J Clin Dermatol. 2006;7(5):306-313.
  6. Min ZS, Tsan C, Xu P, et al. Confluent and reticulated papillomatosis manifested as vertically rippled and keratotic plaques. Postep Derm Alergol. 2014;5:335-337.
  7. Filho FB, Quaresma MV, Rezende FC, et al. Confluent and reticulated papillomatosis of Gougerot-Cateaud and obesity: dermoscopic findings. Ann Bras Dermatol. 2014;89(3):507-509.
  8. Jimbow M, Talpash O, Jimbow K. Confluent and reticulated papillomatosis: clinical, light, and electron microscopic studies. Int J Dermatol. 1992;31:480-483.
  9. Kanitakis J, Zambruno G, Viac J, et al.  Involucrin expression in keratinization disorders of the skin–a preliminary study. Br J Dermatol 1987;117(4):479-486.
  10. Tamraz H, Raffoul M, Kurban M, et al. Confluent and reticulated papillomatosis: clinical and histopathological study of 10 cases from Lebanon. J Eur Acad Dermatol Venereol. 2013;27:e119-e123.
  11. Sakiyama T, Amagai M, Ohyama M. Chronology of confluent and reticulated papillomatosis: spontaneous regression in a case after long-term follow-up may imply transient nature of the condition. J Dermatol. 2015;42(3):335-336.
  12. Berk DR. Confluent and reticulated papillomatosis response to 70% alcohol swabbing. Arch Dermatol. 2011;147(2):247-248.
  13. Tirado-Sanchez A, Ponce-Olivera R. Tacrolimus in confluent and reticulated papillomatosis of Gougerot Cateaud. Int J Dermatol. 2013;52:513-514.