Coexistence of Scrofuloderma and Lepromatous Leprosy in Reaction: A Case Report

ABSTRACT

Leprosy and tuberculosis (TB) are both chronic granulomatous infections caused by bacilli of the genus Mycobacterium. The simultaneous occurrence of cutaneous tuberculosis and leprosy is rare. We report a 56‐year‐old male presenting with painful erythematous nodules and plaques over the face and extremities for 1 week, along with asymptomatic right axillary lesions for 1 year. Examination revealed tender nodules and plaques with ulceration on the face and extremities, and firm, matted subcutaneous nodules with sinus tracts in the axilla. Sensory loss in a glove‐and‐stocking distribution and peripheral nerve enlargement were also noted. Slit‐skin smear demonstrated a Bacteriological Index of 6+, while histopathology of the axillary lesion showed caseous necrosis with epithelioid granulomas. The patient was diagnosed with lepromatous leprosy in type 2 lepra reaction with scrofuloderma and treated with modified multibacillary multidrug therapy, anti‐tubercular therapy, and corticosteroids, achieving a favorable clinical response. This case report aims to describe a rare co‐occurrence of leprosy and tuberculosis, highlighting the immunological interplay between the two conditions and the importance of comprehensive diagnostic evaluation and individualized management in endemic settings.

Key Clinical Message

Although rare today, coexistence of leprosy and cutaneous tuberculosis should be considered in endemic regions, as it poses diagnostic and management challenges; integrated evaluation and coordinated therapy are essential for favorable outcomes.

1. Introduction

Leprosy and tuberculosis (TB) are chronic granulomatous infections caused by Mycobacterium leprae and Mycobacterium tuberculosis , respectively. Although tuberculosis remains endemic in Nepal, the incidence of cutaneous tuberculosis is relatively low (0.03%) [1], and leprosy has been declared “Eliminated” as a public health problem since 2010 [2]. Cutaneous co‐infection with these pathogens is exceedingly rare in contemporary clinical practice, with only a limited number of cases reported in the literature [3, 4]. Such concurrent presentations pose diagnostic and therapeutic challenges and prompt further exploration into their underlying immunological interplay.

2. Case History/Examination

A 56‐year‐old male, farmer by occupation, presented with painful lesions over the face, bilateral upper and lower extremities, and fever for 1 week and asymptomatic lesions over the right axilla for 1 year.

On examination, multiple erythematous tender nodules and plaques, with areas of vesiculation and ulceration over the bilateral arm extensor aspect, right lateral trunk, face and neck were observed (Figure 1). Further examination revealed multiple firm matted subcutaneous nodules with sinus tract openings, interspersed with areas of puckered scarring and overlying adherent hyperpigmented skin localized to the right axilla (Figure 2). Xerosis was present over both legs, on the anterior aspect. Sensory examination demonstrated decreased perception of pain, touch, and temperature in a bilateral glove‐and‐stocking distribution. Motor function was preserved across all extremities. Peripheral nerve assessment revealed Grade 1 enlargement of the radial, ulnar, radial cutaneous, and common peroneal nerves bilaterally, without tenderness.

FIGURE 1.

Multiple erythematous solitary to confluent nodules and plaques, with areas of vesiculation over trunk.

FIGURE 2.

Firm subcutaneous nodules with sinus tracts, interspersed with puckered scars and overlying hyperpigmented, adherent skin over axilla.

3. Differential Diagnosis, Investigations and Treatment

Slit‐skin smear from lesions demonstrated numerous acid‐fast bacilli arranged in globi [Bacterial Index 6+] (Figure 3). Histopathological examination of the lesion over the right axilla showed extensive areas of caseous necrosis in the dermis, surrounded by epithelioid histiocytes. Discrete epithelioid cell granulomas encircled by Langhans‐type giant cells were also observed (Figure 4). Mantoux testing was strongly positive, the Erythrocyte Sedimentation Rate was raised, and chest X‐ray findings were unremarkable.

FIGURE 3.

Ziehl‐Neelsen staining of slit‐skin smear demonstrating numerous acid‐fast bacilli, including globi‐ Bacteriological Index 6+.

FIGURE 4.

Hematoxylin and Eosin (40×) showing epithelioid cell granulomas encircled by Langhans‐type giant cells in dermis from lesion over axilla.

The patient was diagnosed with lepromatous leprosy in type 2 lepra reaction with scrofuloderma and started on Multi‐Bacillary‐Multi‐Drug Therapy (MBMDT) {as per WHO‐recommendation: Rifampicin 600 mg once monthly (supervised), Clofazimine 300 mg once monthly (supervised) with 50 mg daily, and Dapsone 100 mg daily for 12 months} [2] for Leprosy with omission of Rifampicin for the 1st 6 months and Anti Tubercular Therapy Category I (2 months of daily Isoniazid (H), Rifampicin (R), Pyrazinamide (Z) and Ethambutol (E) followed by 4 months of daily Isoniazid and Rifampicin) and short‐course steroids.

4. Outcome and Follow‐Up

The patient is undergoing monthly follow‐up, with a review planned for BI at 12 months. To date, there have been no subsequent reaction episodes.

5. Discussion

An emphasis on the co‐occurrence of Leprosy and TB is clinically and immunologically pertinent, as they together present a complex conundrum. Their shared mycobacterial origin and antigenic similarities predispose to cross‐reactive immune responses, which may influence disease expression and outcomes. Certain factors have been observed to be associated with these coinfections, including a younger male population, multibacillary leprosy undergoing reactional episodes, and a predominant association with pulmonary tuberculosis [3, 4]. All of these are reflected in our case, except for age and an association with scrofuloderma, which is reported in only a countable number of reports in the literature [5, 6].

Cross‐immunity is often debated, with some literature arguing a protective role [7]. Cardenas et al. reported that the presence of antibodies against M. leprae was inversely associated with a positive interferon‐γ release assay for M. tuberculosis infection, supporting the existence of cross‐immunity [8]. The protection, if it exists, seems partial and highly variable. Notably, BCG vaccination, derived from Mycobacterium bovis , appears to confer only partial protection against leprosy, which further supports this notion [3, 9]. Ghunawat et al. and Ghosh et al., however, documented co‐localized lesions of cutaneous tuberculosis and leprosy, providing clinical evidence against their presumed exclusivity [6, 10]. The co‐occurrence of M. tuberculosis and M. leprae may, in part, reflect impaired host immunity, with each pathogen potentially eliciting distinct cell‐mediated responses through differential activation of CD4⁺ and CD8⁺ T‐cell subsets [11]. Nevertheless, Trindade et al. reported no significant defect in the Th1 arm of the cellular immune response in two patients with co‐infection [12].

These immune interactions pose notable clinical challenges. Some authors suggest that tuberculosis infection may predispose individuals to an anergic form of leprosy, while TB antigens could, in turn, trigger lepra reactions, potentially complicating disease outcomes [12]. Conversely, Froes et al. reported that concurrent tuberculosis infection appeared to reduce the incidence of leprosy reactions [13]. Furthermore, co‐morbidities such as malnutrition and immunosuppression have been reported as more frequent in dual infections, and increased morbidity and mortality altogether [4].

Managing co‐infection also poses significant constraints. While corticosteroid therapy used for leprosy reactions has been a concern due to potential tuberculosis susceptibility, a multi‐centre, randomized, double‐blind, placebo‐controlled trial suggests that the risk in patients being treated for lepra reactions may be significantly lower than expected [14]. Treatment may be further complicated by a potential rifampicin resistance from monthly leprosy dosing and drug‐related adverse effects to standard multidrug therapy. This, along with reports of up to one‐quarter of co‐infected patients showing resistance to at least one anti‐tubercular drug, highlights the need for vigilant monitoring and individualized treatment strategies [3].

Concurrent leprosy and cutaneous tuberculosis, though rare today, may occur due to shared epidemiological and host immunological factors. Clinicians in endemic regions should have a high index of suspicion for dual infections and ensure comprehensive diagnostics. Individualized and coordinated treatment strategies are essential to reduce morbidity and optimize the eradication efforts.

Author Contributions

Anupa Khadka: conceptualization, data curation, methodology, writing – original draft, writing – review and editing. Punam Mishra: methodology, writing – review and editing. Akanshya Shrestha: data curation, investigation, writing – review and editing. Gunawati Chaulagain: data curation, investigation, writing – review and editing.

Funding

The authors have nothing to report.

Ethics Statement

The authors have nothing to report.

Consent

Written informed consent was obtained from the patient for publication of this case report and any accompanying images.

Conflicts of Interest

The authors declare no conflicts of interest.

Khadka A., Mishra P., Shrestha A., and Chaulagain G., “Coexistence of Scrofuloderma and Lepromatous Leprosy in Reaction: A Case Report,” Clinical Case Reports 14, no. 1 (2026): e71842, 10.1002/ccr3.71842.

Data Availability Statement

No datasets were generated or analyzed beyond the patient's clinical records, laboratory reports, and biopsy findings. All relevant information is included within the article.