Discussion
CRP is a rare skin condition first described in 19272.
It is asymptomatic in most of the times but can be
pruriginous1. In 2006, Davis et al proposed five
criteria for the diagnosis of the disease3, which were
all displayed by our patient. CRP has been attributed for so long to the
infection with Malassezia furfur1. However, as
observed in our case, studies have been inconsistent with the detection
of yeast in affected patients3. The currently admitted
theory is that CRP is related to a bacteria: Dietzia spp
(anaerobic gram-positive coccus, order of actinomycete). Noninfectious
causes of CRP have been suggested but seem less likely including
endocrine disorders especially insulin resistance explained by the
pro-mitotic and anti-apoptotic effects of hyperinsulinemia, reaction to
UV light and a variant of cutaneous amyloidosis1,4.
Our patient was not obese and did not have diabetes, the eruption was
located on a covered area and histology did not show amyloid deposits
upon Congo red coloration.
Oral minocycline 50-100mg twice daily is the first line
treatment3. Recent reports of the efficiency of
macrolides may make these antibiotics the privileged treatment for CRP,
as they are safer than minocycline5. These medications
are effective because they are antibacterial but most importantly
anti-inflammatory3. Systemic retinoids were previously
used because of their keratoregulatory effect but have now given way to
safer treatments like minocycline and
azithromycin5–7. Lately, Ozdemir et al reported the
effectiveness of oral contraceptives that contain progesterone in the
treatment of CRP in a patient with polycystic ovarian
syndrome8. More recently, Krishnamoorthy et al
described a case of CRP that started to resolve immediately after
bariatric surgery9. These observations strengthen the
hypothesis of the hormonal factor in the genesis of CRP.