Symmetrical centrofacial erythematous plaques and papules: A clinicopathological challenge

Abstract

Facial papular eruptions remain a diagnostic dilemma for the dermatologist with a wide range of inflammatory and infectious conditions manifesting in this manner. Here, we present a case of a 29-year-old, otherwise healthy man from North India with asymptomatic well-defined normoaesthetic symmetrical papules and plaques over the upper and mid-face of 3 months duration. Skin biopsy showed perivascular and periappendageal well-defined collections of foamy macrophages and epithelioid cells in superficial and deep dermis, characteristic of borderline lepromatous leprosy. Though acid-fast stain for lepra bacilli was negative both on lesional biopsy specimen and lesional and ear lobe slit skin smear, a 16s ribosomal ribonucleic acid (16s-r-RNA) polymerase chain reaction on skin biopsy specimen was found to be positive for lepra bacilli. A final diagnosis of borderline lepromatous leprosy in type I reaction was made and the patient received World Health Organization (WHO) multibacillary (MB) multidrug therapy along with oral steroids. This case highlights the unusual localized involvement in a case of MB leprosy lacking all the three cardinal features of leprosy, i.e. sensory loss, peripheral nerve involvement, and acid-fast bacilli positivity on biopsy or slit skin smear but diagnosed on the basis of characteristic histology and positive polymerase chain reaction results.

Keywords

• centrofacial eruption
• foamy macrophages
• localized multibacillary leprosy
• polymerase chain reaction