Tuberculous gluteal abscess coexisting with scrofuloderma and tubercular lymphadenitis
Vandana Mehta Rai MD¹, SD Shenoi MD¹, and Gowrinath MD²
Dermatology Online Journal 11 (3): 14

Introduction

Scrofuloderma, a subcutaneous tuberculosis associated with cold abscess, results from direct extension of an underlying tuberculous focus such as lymph node, bone, or joint to the overlying skin; it presents as firm painless subcutaneous nodules that enlarge gradually and suppurate to form ulcers and sinus tracts. The areas of predilection are the neck, supraclavicular fossa, axilla, and groin. Tubercle bacilli usually can be isolated from the purulent discharge. Metastatic tubercular abscesses occur following hematogenous dissemination of mycobacteria from a primary focus during periods of low resistance; this results in single or multiple cutaneous and subcutaneous lesions in immunocompromised patients. We report the case of an immunocompetent individual who developed tubercular intramuscular cold abscess of the left gluteal region associated with scrofuloderma and adenitis.

Clinical synopsis

Figure 1	Figure 2
Figure 1. Close view of buttock showing a nodule and several papules.
Figure 2. Buttock with multiple serpiginous tracts.

A 23-year-old man presented with skin lesions over the left buttock for 14 months and swelling of the same site for 1 year. The lesions were associated with seropurulent discharge but were otherwise asymptomatic. Movements around the left hip joint were restricted. Examination revealed left sided matted inguinal adenopathy with a diffuse, non-tender, erythematous swelling measuring 15 x 12 cm on the left gluteal region and adjoining thigh. The surface of swelling was studded with multiple skin-colored papules, serpiginous lesions, and two discharging sinuses (Fig. 1). Systemic examination was normal. Routine investigations showed normal blood counts with a raised ESR. Urine analysis and blood biochemistry was within normal limits. HIV serology was negative. Smears and cultures of discharge were negative for bacteria, fungi, and mycobacteria. A punch biopsy from the papule showed features of granulomatous inflammation with caseation. An excision biopsy of left inguinal lymph node showed features of tuberculous lymphadenitis. Biopsy of skin sent for culture grew Mycobacterium tuberculosis. Chest radiograph was normal and X-ray of left hip was normal except for soft tissue swelling. CT scan of left gluteal and thigh region showed multiple subfascial abscesses with enlarged inguinal lymph nodes. Mantoux test with 1 TU showed a strongly positive reaction measuring 25 x 30 mm.

Figure 3	Figure 4
Figures 3 and 4. Skin biopsy

Figure 5	Figure 6
Figure 5. Lymph node biopsy
Figure 6. Mantoux test

Figure 7
Figure 7. After treatment

Antitubercular therapy (ATT) was initiated with rifampicin, isoniazid, pyrazinamide, and ethambutol and 2 months later continued with rifampicin and isoniazid. ATT had to be given for 12 months because swelling persisted at the end of recommended treatment duration of 6 months. It was stopped after swelling resolved and CT scan showed no evidence of residual abscess.

Discussion

The prevalence of tuberculosis (TB) is around 30 million globally and approximately one third of the cases are found in India. Cutaneous tuberculosis is rare and constitutes only about 0.15 percent of all dermatologic outpatients in our country [1]. Cutaneous tubercular abscess can occur from extension of an embolism to subcutaneous tissue (such as pulmonary foci or direct skin inoculation) or from extension of an underlying lymphadenitis, synovitis, or osteomyelitis (as in scrofuloderma) [2]. Vertebral tuberculosis is the most common form of skeletal tuberculosis; gluteal abscess may result from Pott's spine [3], the infection then tracking down along the aorta and its branches to present at the buttock or tracking along the femoral artery to present on the medial aspect of thigh. TB has also been described following subcutaneous or intramuscular injection. Either the syringe, needle or fluid to be injected has been contaminated or the medical attendant has exhaled tubercle bacilli into the patient's skin, which are then introduced by the injection [4]. Our patient presented with gluteal abscess, papular skin lesions, discharging sinuses, and matted lymph nodes. The primary manifestation in our case may have been an inguinal adenitis that triggered the formation of multiple abscesses between the gluteus medius and maximus muscle in the region of left buttock, with overlying papular skin lesions and discharging sinuses without underlying bone involvement [5]. The diagnosis in our case was based on positive Mantoux test, histologic features of caseating granulomatous inflammation, culture, and favorable response to ATT. The absolute diagnostic criteria with conventional methods of smear or culture to demonstrate tubercle bacilli in cases of cutaneous tuberculosis have limitations [6] and newer techniques such as polymerase chain reaction may be useful in view of high specificity and sensitivity [7]. Skin TB should be managed with drug regimens for pulmonary TB, as recommended by the American Thoracic Society and Center for Disease Control. Tuberculous subcutaneous abscesses may develop during chemotherapy for pulmonary TB but this does not necessarily indicate treatment failure [8].

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