Papulonecrotic Tuberculid: A Rare Case Report

Abstract

Tuberculids were originally felt to be related to an allergic response to tubercle bacilli in a
patient with tuberculosis at a remote site. They are currently believed to be the result of hematogenous
dissemination of organisms from an internal focus to the skin, where they incite
a cutaneous inflammatory response. Papulonecrotic tuberculid (PNT) is a form of tuberculids
that as the name implies presents clinically as necrotic papules. Herein, we report a case of
59-year-old man who presented with recurrent asymptomatic symmetrical necrotizing papules
scattered on his trunk for 9 months. The patient has also crusted plaque on his right forearm.
Two skin biopsies were made, one from papulonecrotic lesion on his trunk and the other one
from the crusted plaque on his right forearm. The crusted plaque on the forearm showed granulomatous
cellular infiltrates and caseation necrosis in the dermis, whereas the papulonecrotic
lesions showed patchy perivascular mononuclear cellular infiltrates as well as granulomatous
cellular infiltrates in the dermis. Tuberculin test was positive. A diagnosis of lupus vulgaris on
the forearm and PNT on the trunk were made based on clinicopathological findings. The patient
was seen by chest physician where there was no systemic involvement. Patient was treated successfully
with anti-tuberculosis drugs for 9 months with complete resolution of all skin lesions.