Confluent and reticulated papillomatosis (CRP) was first described in 1927, and is also called “Gougerot-Carteaud Syndrome” after the scientists who elucidated its findings. It is a very rare condition, which consists of the eruption of numerous small papilloma-like lesions usually starting over the front of the torso and spreading to both sides, upwards, and downwards. Thus the final lesion is usually extensive.
CRP begins as very small bluish or brownish lesions, which look rather like warts, but are joined together to form a confluent lesion. The patterns look lacy at the edges due to the merging of the irregular lesions within the margins. They are characterized by scaling papules, showing hyperkeratosis. In some cases the lesions appear atrophic, or as a vertical pattern with rippling. Dermoscopy shows brown pigmented lesions with white scales, arranged in furrows and ridges.
The initial lesions begin in the midline anteriorly and posteriorly before spreading to cover the whole area up to the neck and the abdomen, the axillae, and the breasts. In a few cases lesions have been reported to appear on the face, the shoulders, and the genital areas. In most patients, the lesions do not produce any symptoms, but may itch a little in some cases.
There is a predilection for females except in the Japanese. The onset of the condition follows puberty in typical cases, and it becomes chronic, waxing and waning for years. Observation has shown that the lesions stabilize in a few years, having extended over a larger area, and remain as such.
The cause of CRP is not yet known but there is increased keratin production and a high skin cell turnover. It is thought that the condition may be due to:
- Hormonal fluctuations, because of the association of CRP with metabolic syndromes that occur secondary to hormone level alterations such as diabetes, thyroid disturbances, or obesity.
- Dysregulation of cell growth and differentiation, because some medications which control epidermal cell growth have a beneficial effect on CRP.
- Other possibilities include yeast or bacterial infection, or hereditary factors.
Diagnosis and Treatment
Since the etiological factors are as yet unknown, and the course of the disease is benign and stable, the only reason to treat it is for cosmetic purposes. Different modes of treatment have been used, including minocycline, a broad-spectrum antibiotic, other antibiotics, and systemic or topical antifungals. Vitamin A derivatives have also been used, such as topical application of tretinoin, to regulate skin cell turnover and help elevated rough areas to smoothen out with time. Systemic retinoids are also useful but their use is often teratogenic and should be used only with extremely strict contraceptive measures.
Other medications which are thought to be helpful include calcipotriol, used as a topical cream. Supportive treatment is directed at improving accompanying health issues such as weight loss.