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Papulonecrotic tuberculid-clinicopathologic and molecular features of 12 Indian patients
Rajalakshmi Tirumalae1, Inchara K Yeliur1, Meryl Antony1
1Departments of Pathology & Dermatology, St. John's Medical College & Hospital, Bangalore, India.
Background:
Papulonecrotic tuberculid (PNT) is said to be a hypersensitivity reaction to M. tuberculosis. Some reports indicate that organisms are demonstrable by polymerase chain reaction (PCR).
Methods:
We describe 12 patients with PNT over 6 years. We reviewed the histopathologic features, clinical data and follow-up. PCR for M. tuberculosis DNA was done in all cases.
Results:
There were 7 men and 5 women. The ages ranged from 3-58 years. Upper limbs were commonly involved (8 cases). All patients had multiple papulonodular lesions, 5 showed ulceration and scarring. Mantoux test was strongly positive in all. Seven patients had systemic tuberculosis. On microscopy, necrosis was seen in 11 cases, varying from minimal to extensive. Epithelioid granulomas were common, except for 1 case with palisading and interstitial patterns. The infiltrate showed mostly lymphocytes, while 3 cases showed eosinophils. Vasculitis was seen in 8 cases. Two cases had dermal mucin, one also with interface dermatitis. This patient had concurrent LE. Mycobacterial DNA was detectable by PCR in 3 cases. Seven patients showed improvement/resolution of lesions on treatment.
Conclusions:
PNT is a rare disease. A positive PCR reiterates the question whether these are "tuberculids". PNT may be better classified as true cutaneous tuberculosis and patients screened for systemic disease.
Insights
Papulonecrotic tuberculid (PNT) is a rare skin condition. Detecting Mycobacterium tuberculosis DNA via PCR in some cases suggests PNT might be a form of cutaneous tuberculosis requiring systemic screening.
Area of Science:
- Dermatology
- Infectious Diseases
- Microbiology
Background:
- Papulonecrotic tuberculid (PNT) is considered a hypersensitivity reaction to Mycobacterium tuberculosis.
- Some studies suggest the presence of M. tuberculosis organisms in PNT lesions, detectable by polymerase chain reaction (PCR).
Purpose of the Study:
- To describe the clinical and histopathologic features of 12 patients diagnosed with PNT.
- To investigate the presence of M. tuberculosis DNA in PNT lesions using PCR.
- To evaluate treatment outcomes and disease classification.
Main Methods:
- Retrospective review of 12 PNT patients over 6 years.
- Analysis of histopathologic features, clinical data, and follow-up.
- Polymerase chain reaction (PCR) for M. tuberculosis DNA in all cases.
Main Results:
- The study included 12 patients (7 males, 5 females; ages 3-58).
- Upper limbs were most commonly affected (8 cases); lesions were papulonodular, with 5 showing ulceration/scarring.
- Mycobacterial DNA was detected by PCR in 3 cases; 7 patients showed improvement with treatment.
Conclusions:
- PNT is a rare condition, and positive PCR results raise questions about its classification as a
- The findings suggest PNT could be a manifestation of true cutaneous tuberculosis, necessitating screening for systemic disease.
- PNT management may benefit from considering it as true cutaneous tuberculosis.
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