Welcome on Therapeutics in Dermatology !
Confluent and reticulated papillomatosis (CRP) described in 1927 by Goujerot and Carteaud is a rare disease that is often not recognised by physicians or misdiagnosed. It is characterised by asymptomatic brownish, small (1 to 5 mm) hyperkeratotic papules that unite to form plaques of several millimetres. The lesions begin and coalesce in the intermammary and interscapular areas and then spread in a centrifugal manner to other anatomical areas (epigastrium, back, shoulders, armpits or neck and more rarely, pubic area, face and limbs) forming a reticular pattern. The disease typically affects adolescents or young adults and is not predominant in any race or gender. Most cases are sporadic rather than familial. Confluent and reticulated papillomatosis is sometimes accompanied by endocrine disorders (diabetes, obesity, thyroid disease, polycystic ovary syndrome), atopy, or associated with the intake of medicinal substances such as lithium, or exposure to the sun or genodermatosis. In some cases, after spreading for a few years, the lesions may remain permanently unchanged.
Histological examination of skin specimens shows hyperkeratosis and focal parakeratosis, papillomatosis (sometimes not present ), moderate, irregular and inconstant acanthosis, inconspicuous perivascular lymphohistiocytic infiltrate of the skin and discrete basal layer hyperpigmentation [4, 15]. Systematic tests should include PAS and Congo Red staining (differential diagnosis) and scale sampling (scotch-tape test to strip off scales for culture) to test for Malassezia spores (e.g.: oval Pityrosporum).
Conditions that must be considered in a differential diagnosis include pityriasis versicolor, acanthosis nigricans (with which CRP may be combined) and pseudoacanthosis nigricans, Darier disease, Macular and pigmented amyloidosis and seborrhoeic dermatitis.
The etiopathogenesis of the disease is unknown and several hypotheses have been put forward, the main ones including genetic keratinization disorder and/or abnormal response of the host to colonisation of the skin by Malassezia or by bacteria of the follicles. There have been reports of actinomyces being found in CRP lesions.
× N.B. : This limited content is for the general public. If you are a health professional, click here to register for free and gain access to a dedicated deeper content.
If you already have an account, log in!
Therapeutics in Dermatology, Fondation René Touraine © 2001-2012