Multifocal tuberculosis

Introduction

Cutaneous tuberculosis makes up a small proportion of all cases of extra pulmonary tuberculosis which in turn constitutes about 10% of all cases of tuberculosis. Tuberculous gumma, a form of tuberculosis which arises independently of any apparent adjacent tuberculous focus, and is the result of haematogenous dissemination from a primary focus during periods of bacillaemia and lowered resistance.[1] A tuberculous gumma presents either as a firm subcutaneous nodule which slowly softens or as an ill defined fluctuant swelling. The extremities are more often affected than the trunk. The overlying skin gradually breaks down to form an undermined ulcer, often with sinuses. The subsequent changes resemble those of scrofuloderma with bluish surrounding skin being tethered to inflammatory mass.

Tuberculous dactilitis constitutes 2.5% of skeletal tuberculosis and is uncommon after the age of 6 years. The hand is more frequently involved than foot.[2] Any osteoarticular tubercular lesion is the result of a haematogenous dissemination from the primary infected visceral focus. The primary focus may be active or quiescent, apparent or latent either in the lungs or in the lymphglands of mediastinum and mesentery or cervical regon or kidneys or other viscera.

Case Report

A 19-year-old salesman presented with multiple swellings and discharging sinuses over the small joints of hands and feet of 5 months duration. Patient first noticed swelling over the left ankle which gradually increased in size and burst open and discharged purulent material and formed sinus. Later he developed similar swellings and sinuses over right index finger, base of right thumb, back of elbow, dorsum of left hand, left little finger, base of middle three toes of right foot and great and little toes of left foot. The swellings were associated with pain.

Cutaneous examination revealed multiple swellings distributed over dorsum of left hand and middle phalanx of left index finger and base of left little finger. The swellings were fusiform, fluctuant, non-tender, varying from 1 cm. to 3 cms in length. Multiple sinuses discharging purulent material were noted over base of right thumb, base of left little finger, lateral aspect of left heel and base of left little toe and point of right elbow. There was hyperpigmentation and oedema surrounding the sinuses. Purulent discharge could be expressed from few sinuses, puckered scars were present over the base of III/IV toes and over great toe of left foot, and lateral aspect of right thenar eminence. The scars were fixed to the underlying tissue. Hair, nail, mucous membranes and genitalia were normal. Systemic examination did not reveal any abnormality. [Figure - 1]

He was provisionally diagnosed as a case of tuberculous gumma. Sporotrichosis, actinomycosis, sarcoidosis were the other differential diagnoses that were considered. Blood sugar, blood urea levels were within normal limits. ESR was 51 Mm 1st hour. X-ray chest PA view showed apical cavity and infiltration suggestive of tuberculosis. Sputum for AFB was negative. Mantoux test was positive (16mm). X-ray both hands showed irregular osteolytic lesions with pathological fracture of (left) proximal phalanx of little finger and osteolytic destruction with sclerosis of 1st metacarpal of right hand. Smear taken from the pus was negative for AFB. Smear for fungal elements was negative. Pus for AFB culture on Lowenstein Jensen medium was positive. Pus for fungal culture was negative. Pus for bacterial culture was negative. VDRL was non-reactive. HIV test I and II was negative. Ultrasound of abdomen revealed normal study. Biopsy taken from swelling on the dorsum of left hand showed tubercular granulation tissue. Both biopsy and culture have confirmed the diagnosis of tuberculous gumma. The X-ray chest and X-ray both hands have also suggested tuberculous infection. Hence it is concluded that the tuberculous infection in this case has spread by haemotogenous route. The patient was started on anti tuberculosis treatment. With treatment, patient stopped developing new lesions and old lesions were healing. [Figure - 2]

Discussion

Tuberculosis has involved multiple systems in the reported case. The patient had multiple tubercular gummata, pulmonary tuberculosis and dactilitis which led to pathological fracture. The occurrence of the gumma is uncommon. Farine et al had reported 2 case of tuberculous gumma in their study of 11 cases of cutaneous tuberculosis.[3] Tuberculous infection involving multiple systems like skin, lungs and bones as in the reported case is rare. Baril et al have reported a case of cutaneous tuberculosis caused by Mycobacterium africanum, which was associated with bilateral nodular scleritis, nasal septal perforation and with pulmonary tuberculosis.[4] In recent years cutaneous infection with Mycobacterium tuberculosis with an atypical clinical appearance have become more common because of increased number of immunocompromised patients. Corbett et al have reported cases of disseminated cutaneous tuberculosis in HIV positive patients all of whom also had pulmonary tuberculosis.[5] However the reported case had multisystem involvement even though he was HIV negative.

The case is reported for its rare association of tuberculous gumma with pulmonary tuberculosis along with tuberculous dactilitis.