Papulonecrotic tuberculid (PNT) is characterized by symmetrically distributed erythematous papules that often ulcerate and heal with a varioliform scar. It affects patients with a moderate-to-high degree of tuberculin hypersensitivity.1 In the current classification of cutaneous tuberculosis, PNT is included in the group of tuberculids. The pathogenic relationship between tuberculids and Mycobacterium tuberculosis has been the subject of controversy, since M tuberculosis has never been cultured from these lesions. For many authors, they represent hypersensitivity reactions to hematogenously disseminated bacilli or mycobacterial antigens. Recently, the DNA of M tuberculosis has been detected by polymerase chain reaction (PCR) amplification in the lesions of PNT and other tuberculids.2-4 The aim of this study was to demonstrate the presence of M tuberculosis DNA in the lesions of PNT.
Materials and Methods.
We selected skin biopsy specimens with histopathologic features consistent with PNT from patients with clinically suggestive lesions and positive tuberculin
Baselga E, Margall N, Barnadas MA, Moragas JMD. Mycobacterium tuberculosis DNA in Papulonecrotic Tuberculid. Arch Dermatol. 1996;132(1):92-94. doi:10.1001/archderm.1996.03890250106024