Sporotrichoid cutaneous tuberculosis in the peruvian amazon: case report

ABSTRACT Cutaneous tuberculosis is a rare presentation of Mycobacterium tuberculosis infection. We present the case of a woman without important medical history, with a disease period of one year and a half, characterized by sporotrichoid-like lesions, with lymphocutaneous dissemination in the right upper limb, and with slowly progressive evolution. The histopathological tests revealed Langhans type giant cells and scarce necrosis. The patient received therapy with a sensitive antituberculous scheme, and evolved favorably.


INTRODUCTION
Tuberculosis caused by Mycobacterium tuberculosis is the infectious disease with the highest mortality rate, after COVID-19 (1) . Cutaneous lesions represent 1 -1.5% of all manifestations of extrapulmonary tuberculosis, and are currently classified according to their morphological-clinical pattern, the route of acquisition and the immunological status of the host (2,3) .
One of the main forms of infection is by "primary tuberculosis inoculation, " which occurs by exogenous inoculation in a population not previously sensitized to M. tuberculosis or in children not immunized against bacillus Calmette-Guérin (BCG). It starts with a nodular lesion on the face or upper or lower extremities, which eventually ulcerates after 2 or 3 weeks, and there is also non-painful lymphadenopathy associated with lymphocutaneous complex analogous to Ghon's complex in pulmonary infection (4) . Diagnosis is done by early biopsy, showing a neutrophilic infiltrate that evolves to produce a necrotizing tuberculous granuloma with the presence of multiple acid-fast bacilli (5,6) .
There are few reports of cases of tuberculosis due to primary inoculation with a sporotrichoid pattern and lymphocutaneous spread, which complicates its diagnosis. We report a case of chronic skin lesions with painless shallow ulcers with granulomatous base and lymphocutaneous spread. The anatomopathological study described cutaneous tuberculosis; and therefore, antituberculosis therapy was initiated with good response.

Patient information
We present the case of a 14-year-old female patient from the city of Iquitos, in the Peruvian Amazon, with no medical history, no loss of appetite, and no weight loss or nocturnal temperature increase. She had 18 months of illness before hospital admission. The main symptom was an increase in volume on the dorhttps://doi.org/10.17843/rpmesp.2022.393.10919 sum of the right hand, initially painless, which progressed from a nodular lesion to an ulcerated lesion, to later develop an apparently lymphatic dissemination throughout the right upper extremity, without other accompanying symptoms. She attended the outpatient service of the dermatology department of the Regional Hospital of Loreto. She did not report contact or recent travel, neither any injury risk factors associated with the onset of signs and symptoms.
She had no previous history of tuberculosis or use of immunosuppressant drugs, nor did she report any close or family contact with patients infected with tuberculosis. The patient mentioned that she went to a private clinic without a successful outcome, she did not disclose the treatment received. She did not undergo immunological tests for tuberculosis such as Mantoux test or QuantiFERON Gold test.

Clinical findings
During physical examination, a lesion with erythematous, soft bottom extending over the dorsum of the hand was found on the inner side of the right arm. Serosanguinous secretion was observed after incision. In addition, there was evidence of ulcers with raised, crusty and everted edges with presence of granulation tissue at the base ( Figure 1). No regional lymphadenopathy was found by palpation, only a scrofuloderma lesion was evidenced in the right armpit. Overall, there were ten cutaneous lesions with lymphocutaneous spread over the entire right upper extremity.

Therapeutic intervention
Treatment was initiated with a first-line drug-sensitive antituberculosis scheme: pyrazinamide 900 mg; ethambutol 700 mg; rifampicin 350 mg, and isoniazid 175 mg/day.

Follow-up and results
Currently the patient continues to receive antituberculosis therapy and with apparent resolution of the lesions.

DISCUSSION
Cutaneous tuberculosis simulating sporotrichosis differs from other types of subcutaneous tuberculosis, such as scrofuloderma, because of an apparent clinically underlying tuberculous site. This site was not found in the case we are presenting. observed in children and young people (8,9) . The initial diagnosis of this condition, made by biopsy, shows the presence of high loads of acid-alcohol-fast-bacilli (AAFB), however, in long cases, these bacilli decrease, with presence of epithelioid granuloma and Langhans type giant cells (5,(10)(11)(12) .
Sometimes the special Ziehl-Neelsen staining of sputum samples does not reveal the presence of the microorganism in the sample (8)(9)(13)(14)(15) , as in this case. Lesions can evolve for a long time and will continue to appear if treatment is not initiated. The cutaneous lesions diminish in response to specific treatment for tuberculosis, with complete resolution after five months of anti-tuberculosis therapy; however, there may be a rapid evolution after two months of starting this therapy (9,14,16) .
In our case, the patient continues in the second phase of antituberculosis therapy with a sensitive scheme, with resolution of the primary site and without new lesions.
The mechanism of infection in this case is unknown and primary inoculation of tuberculosis is suspected, because of the localization in upper and lower limbs. This unusual presentation is accompanied by lymphatic spread, with exogenous inoculation (7,9) .
One of the limitations of this report is that molecular tests for In conclusion, the clinical presentation of cutaneous tuberculosis should be considered during the differential diagnosis of sporotrichosis-like skin lesions, especially in patients with no antibiotic or antifungal response, and in areas with a high incidence of tuberculosis.
Authors' contributions: all authors participated in the study concept and design, data interpretation, drafting and critical revision of the article, and approval of the final version.

Conflicts of interest: no conflicts of interest were declared.
Ethical criteria: informed consent was obtained from the patient.
The study was evaluated and approved by the Institutional Ethics and Research Committee of the Hospital Regional de Loreto (File 5786/2022) and has institutional authorization for its execution and publication (Oficio 2661 2022-GRL-DRS-L/30.50).