Clinical and therapeutic judgment regarding confluent and reticulated papillomatosis of Gougerot and Carteaud

By Warren R. Heymann, MD, FAAD
Feb. 5, 2025
Vol. 7, No. 5

Congratulations to Aaron Judge for setting the American League seasonal record in 2023 for the most home runs — 62 — a remarkable feat. I was only six years old when Roger Maris* slammed his 61st home run eclipsing the 60 Babe Ruth hit in 1927. Maris’s name was followed by an asterisk, denoting that his record was reached in a 162-game season, compared to Ruth’s 154 games. (The dermatological relevance is that during the final weeks of the 1961 season, stressed by hostility from the media and fans, Maris noted losing hair in clumps — described as bald spots by his barber (1,2) — I presume this was alopecia areata). Many consider the 1927 Yankees the ultimate baseball team. That was also a banner year for dermatologic teamwork as Gougerot and Carteaud described “papillomatose pigmentée innominée” (“innominate pigmented papillomatosis”) (3) subsequently named confluent and reticulated papillomatosis (CARP) of Gougerot-Carteaud. CARP is still an enigmatic disease as its recognition as a distinct disorder approaches its 100th anniversary.

CARP is characterized by asymptomatic scaly, hyperpigmented papules and plaques that are reticulated at the periphery and confluent in the center. Lesions are distributed on the intermammary region, epigastric area, upper back, and less commonly, the neck, axillae, shoulders, and face. Hypopigmented CARP has been described. Adolescents and young adults are most commonly affected; CARP may be seen in men and women. (4)

McKenzie et al retrospectively identified 111 children with CARP. The mean age at CARP diagnosis was 14.6 years (range 6–18 years), sex was evenly distributed, and the majority of patients identified as either White Hispanic (60.4%) or Black (28.8%). Most children were classified as either “overweight” (18.0%) or “obese” (70.3%) by body mass index percentile at the time of CARP diagnosis. Nearly 65% of the cohort had concomitant acanthosis nigricans (AN) on the exam. Other common comorbidities included hyperlipidemia (21.6%), hypertension (9.9%), polycystic ovarian syndrome (PCOS) (17.9% of female patients), and type 2 diabetes mellitus (T2DM) (5.4%). Family history was positive for T2DM in 46.8% and/or hypertension in 42.3%. (5) In a study of 68 CARP patients compared to 399 randomly selected acne patients, Xiao et al reported a median age of 14 years and female predominance. In a multivariable analysis, patients with CARP were significantly more likely to identify as Black, be overweight or obese, and have concurrent AN compared to control patients. (6) Rare cases of familial CARP have been reported — the inheritance being autosomal dominant. Interestingly, in the kindreds reported by Henderson Berg and Pehr, no patients had any evidence of obesity, AN, endocrine, or metabolic disorders. (7)

The main differential diagnoses of CARP (8) include AN and tinea versicolor. Other disorders such as Darier disease, Dowling-Degos disease, Galli-Galli disease, dyskeratosis congenita, and macular amyloidosis are easier to differentiate clinically and histologically. Biopsies of CARP demonstrate hyperkeratosis, papillomatosis, focal acanthosis, and increased melanin pigmentation (and melanosomes). (9) In their histological study comparing AN to CARP, Park et al. concluded that “the histologic differences alone do not seem sufficient to precisely distinguish the two disorders. Thus, a clinicopathologic correlation should remain the mainstay of diagnosis.” (10)

The etiology of CARP is puzzlement and perhaps is multifactorial in predisposed patients. This is eloquently summarized by Banjar et al: “Abnormal host reaction to Pityrosporum organisms or bacteria, hyperinsulinemia, insulin resistance, Cushing disease, menstrual irregularities, thyroid disease, pituitary dysfunction, hirsutism or hypertrichosis, obesity, acanthosis nigricans, ultraviolet light exposure, amyloidosis, and the disorder of keratinization with overexpression of keratin-16 have been suggested to play a role in the development of the disease.” (4) Given the excellent clinical response of CARP to tetracyclines, often attributed to their anti-inflammatory effects, it is difficult to discount an antibacterial effect, especially in light of the discovery of Dietza papillomatosis, an aerobic, Gram-positive actinomycete isolated from the skin of an immunocompetent man with CARP. (11)

Astonishingly, the use of “cyclines” to treat CARP was first reported by Carteaud himself in 1965. (12) There are no well-established guidelines for managing CARP — various therapies have been utilized, including other antibiotics, antifungals, and retinoids. In a study of 278 treatment regimens encompassing 192 CARP patients, Mufti et al confirmed that oral tetracyclines were the most commonly reported drug class used as monotherapy (44.6%; n = 124/278), achieving complete resolution (CR) in 59.7% (n = 74/124) and partial resolution (PR) in 22.6% (n = 28/124) of cases, with a mean resolution period of 51.8 days. Minocycline was the most frequently used tetracycline (91.9%; n = 114/124), achieving CR in 61.4% (70/114) and PR in 21.1% (n = 24/114) of cases within 51.0 days. Other oral antibiotics (amoxicillin and azithromycin) were administered in 9.4% (n = 26/278) of cases, achieving CR or PR within 57.9 days in 92.3% (n = 24/26) of cases. (13) Because of the risk of adverse reactions to minocycline, my first-line choice is doxycycline. (14) Recent reported successful therapeutic interventions for CARP include topical sirolimus (15), methotrexate [although the clinical photographs were reminiscent of psoriasis to my eye] (16), antiretroviral therapy in an HIV-positive patient with CARP (17), and bariatric surgery (18). The diagnosis of CARP may serve as a segue to a discussion of weight reduction for the disorder and the patient’s overall health.

Aaron Judge is a hero in baseball circles. Your clinical judgment in appropriately diagnosing and treating CARP will make you an all-star with your patients.

Point to Remember: Confluent and Reticulated Papillomatosis of Gougerot and Carteaud is usually seen in adolescents and young adults. Antibiotics (most commonly minocycline or doxycycline) are first-line therapy. The etiology of CARP remains to be determined, and further studies will judge its precise relationship to acanthosis nigricans.

Our expert’s viewpoint

Lorraine Rosamilia, MD, FAAD
Medical dermatologist for DuBois Dermatology & Cosmetics and DermDox Dermatology Centers Telehealth in central Pennsylvania

I distinctly remember the moment during medical school when one of my mentors showed me and my classmates a photo of a striking skin eruption. “Folks, this is ‘confluent and reticulated papillomatosis…’ (and I thought that was the end of the description) ‘…of Gougerot and Carteaud’, or CARP, for short.” It was difficult not to either grimace (because you had no interest in dermatology and deemed it a specialty of verbose nerds) or grin (because you knew that you had found your people).

To wax on for paragraphs about a benign and relatively asymptomatic eruption may seem inane. Alas, the beauty of our specialty lies in our ability to thoroughly examine and describe a lesion or eruption, narrow down differentials that often include rare, malignant, and morbid conditions, use clinicopathologic correlation to decode the most likely diagnosis, and foremost, inform the patient of not only the name and nature of the condition but also its tendency for any sort of health consequence or association (such as metabolic syndrome). Further, we recommend ways in which the appearance of the eruption, which may have been the primary reason that the patient waited for months for the appointment and presented in the first place, could be improved and highlight the risks/benefits of such treatments.

Home run.

1. Shmuck P. Maris’s chase was stress test 1961: In pursuit of Babe Ruth’s home run record, Roger Maris faced hostility from fans and the media, a far cry from the adulation Mark McGwire is getting now. The Baltimore Sun, September 6, 1998. https://www.baltimoresun.com/news/bs-xpm-1998-09-06-1998249192-story.html

2. https://sportslifer.wordpress.com/2020/09/11/maris-losing-hair-feeling-pressure-of-hr-chase/

3. Henderson Berg MH, Pehr K. Familial Confluent and Reticulated Papillomatosis in 2 Kindreds Including 3 Generations. J Cutan Med Surg. 2018 May/Jun;22(3):330-332. doi: 10.1177/1203475417738968. Epub 2018 Apr 22. PMID: 29681161.

4. Banjar TA, Abdulwahab RA, Al Hawsawi KA. Confluent and Reticulated Papillomatosis of Gougerot and Carteaud: A Case Report and Review of the Literature. Cureus. 2022 Apr 28;14(4):e24557. doi: 10.7759/cureus.24557. PMID: 35651451; PMCID: PMC9138193.

5. McKenzie PL, Ogwumike E, Agim NG. Confluent and reticulated papillomatosis in pediatric patients at an urban tertiary care center. Pediatr Dermatol. 2022 Jul;39(4):574-577. doi: 10.1111/pde.15023. Epub 2022 May 9. PMID: 35535014.

6. Xiao TL, Duan GY, Stein SL. Retrospective review of confluent and reticulated papillomatosis in pediatric patients. Pediatr Dermatol. 2021 Sep;38(5):1202-1209. doi: 10.1111/pde.14806. Epub 2021 Sep 24. PMID: 34561886.

7. Henderson Berg MH, Pehr K. Familial Confluent and Reticulated Papillomatosis in 2 Kindreds Including 3 Generations. J Cutan Med Surg. 2018 May/Jun;22(3):330-332. doi: 10.1177/1203475417738968. Epub 2018 Apr 22. PMID: 29681161.

8. Basu P, Cohen PR. Confluent and Reticulated Papillomatosis Associated with Polycystic Ovarian Syndrome. Cureus. 2019 Jan 25;11(1):e3956. doi: 10.7759/cureus.3956. PMID: 30956909; PMCID: PMC6436673.

9. Le C, Bedocs PM. Confluent And Reticulated Papillomatosis. 2022 Jan 2. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan–. PMID: 29083642.

10. Park YJ, Kang HY, Lee ES, Kim YC. Differentiating confluent and reticulated papillomatosis from acanthosis nigricans. J Cutan Pathol. 2015 Dec;42(12):944-952. doi: 10.1111/cup.12581. Epub 2015 Sep 28. PMID: 26264983.

11. Jones AL, Koerner RJ, Natarajan S, Perry JD, Goodfellow M. Dietzia papillomatosis sp. nov., a novel actinomycete isolated from the skin of an immunocompetent patient with confluent and reticulated papillomatosis. Int J Syst Evol Microbiol. 2008 Jan;58(Pt 1):68-72. doi: 10.1099/ijs.0.65178-0. PMID: 18175685.

12. Sassolas B, Plantin P, Guillet G. Confluent and reticulated papillomatosis: treatment with minocycline. J Am Acad Dermatol. 1992 Mar;26(3 Pt 2):501-2. doi: 10.1016/s0190-9622(08)80587-7. PMID: 1564161.

13. Mufti A, Sachdeva M, Maliyar K, Lansang RP, Lytvyn Y, Sibbald RG, Yeung J. Treatment outcomes in confluent and reticulated papillomatosis: A systematic review. J Am Acad Dermatol. 2021 Mar;84(3):825-829. doi: 10.1016/j.jaad.2020.08.133. Epub 2020 Nov 10. PMID: 33187737

14. Heymann WR. Confluent and reticulated papillomatosis, prurigo pigmentosa, and antibiotic preference. J Am Acad Dermatol. 2023 Aug;89(2):233-234. doi: 10.1016/j.jaad.2023.05.066. Epub 2023 Jun 2. PMID: 37271454.

15. Kurtyka DJ, Burke KT, DeKlotz CMC. Use of Topical Sirolimus (Rapamycin) for Treating Confluent and Reticulated Papillomatosis. JAMA Dermatol. 2021 Jan 1;157(1):121-123. doi: 10.1001/jamadermatol.2020.4083. PMID: 33175118.

16. Nunes de Mattos AB, Brummer CF, Funchal GDG, Nunes DH. Use of methotrexate in an exuberant case of confluent and reticulated papillomatosis of Gougerot and Carteaud in a teenager. An Bras Dermatol. 2019 Nov-Dec;94(6):717-720. doi: 10.1016/j.abd.2018.09.002. Epub 2019 Oct 26. PMID: 31789249; PMCID: PMC6939189.

17. Ballout RA, Helou G, Maatouk I. Antiretroviral-responsive confluent and reticulated papillomatosis: a case report of an unusual association. Oxf Med Case Reports. 2019 Oct 31;2019(10):omz099. doi: 10.1093/omcr/omz099. PMID: 31772738; PMCID: PMC6822602.

18. Krishnamoorthy M, Nadler E, Vaidya S. Resolution of confluent and reticulated papillomatosis after bariatric surgery. Clin Obes. 2021 Feb;11(1):e12427. doi: 10.1111/cob.12427. Epub 2020 Nov 8. PMID: 33164331.

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