Lichen scrofulosorum and immune thrombocytopenic purpura in a child with tuberculosis.

To the Editors: Lichen scrofulosorum is a rare manifestation of cutaneous tuberculosis (TB) characterized by closely grouped reddishbrown minute papules, often perifollicular and is believed to be due to hematogenous spread of mycobacteria. Thrombocytopenia is also an uncommon feature in patients with tuberculosis. We report a 12-year-old girl with lichen scrofulosorum over her trunk, immune thrombocytopenia induced petechiae over the body with mediastinal lymphadenopathy, who responded to methylprednisolone and antitubercular therapy. A 12-year-old girl was admitted for high grade fever and diffuse papular rash of 15 days duration. The rash was limited to her chest, abdomen, and back and was associated with mild itching. Five days after the onset of fever she developed epistaxis which worsened over a period of 2 days and necessitated nasal packing. On the same day, the patient noticed a new rash, reddish in color, nonelevated, nontender, and pin point on her limbs and gradually involving the whole body. There was no history of hematologic or liver disease and the patient did not report any chronic drug intake. Clinical examination was significant for multiple grouped reddish brown follicular and extrafollicular lichenoid papules involving the front and back of the trunk suggestive of lichen scrofulosorum (Fig., Supplemental Digital Content 1, http://links.lww.com/INF/A501). She also had multiple petechiae predominantly over her limbs. Initial laboratory investigations revealed hemoglobin of 9.2 g/dL, total leukocyte count (TLC) 11.8 10/L with polymorphs 68% and lymphocytes 31%. Initial platelet count was 20 10/L with paucity of platelets in the peripheral smear. Prothrombin time and activated partial thromboplastin time were normal. The liver and renal function tests were normal. Tests for antinuclear antibody, Coombs test and serologies for HIV, hepatitis-B, hepatitis-C, Ebstein-Barr virus, cytomegalovirus, and varicella zoster and dengue were negative. Blood cultures were sterile. Tuberculin skin test (5TU, purified protein derivative) was positive producing a 22-mm induration. Chest radiograph was significant for superior mediastinal widening, which on computed tomography, revealed multiple lymph nodes in the mediastinum with areas of necrosis and calcification. Sputum for acid fast bacilli was negative. Bone marrow aspiration showed increase in size and number of megakaryocytes with normal myeloid and erythroid precursors without any evidence of acid fast bacilli or granuloma. Skin biopsy showed dermal granulomatous inflammation with negative Ziehl-Neelsen staining. Ultrasonography of abdomen was normal. Two days after admission, her platelet count fell to 5 10/L which necessitated 2 units platelet transfusion. She was treated with intravenous methyl-prednisolone (1000 mg) for 3 days and followed by oral prednisolone (1 mg/kg). Antitubercular therapy consisting of isoniazid, rifampin, ethambutol, and pyrazinamide was started. The child responded to treatment, her platelet count started rising reaching 112 10/L on day 7 of therapy. Fever and petechiae subsided completely and the papular lesions started decreasing gradually. Prednisolone was continued at 1 mg/kg for 6 weeks and then subsequently tapered. After 2 months of antitubercular therapy, she was changed to a maintenance regimen of isoniazid and rifampicin for 4 months. Last evaluated 4 months after the onset of therapy, the patient was asymptomatic and doing well. Cutaneous tuberculosis is an uncommon presentation of tuberculosis and can be often missed. It is also highly varied and range from lupus vulgaris, scrofuloderma, or tuberculosis verrucosa cutis in a previously sensitized individual, to military tuberculosis of skin and tuberculous chancre is a previously nonexposed individual. There are also a group of less well understood lesions (tuberculids) which are believed to result from hypersensitivity. Lupus scrofulosorum is a rare form of tuberculid, first recognized by Hebra in 1868, usually seen in children and young adults. It consists of small firm follicular and parafollicular lichenoid papules covered by fine scales confined mainly to the trunk. The lesion may persist for months and may resolve spontaneously. The cutaneous manifestion of our patient were consistent with lichen scrofulosorum and was confirmed by skin biopsy. In addition our patient subsequently developed petechiae which on evaluation was found to be due to immune thrombocytic purpura (ITP). Thrombocytopenia is an uncommon manifestation in TB and currently there have been only 4 reports of ITP in children with tuberculosis. To our knowledge, this is the first report of 2 extremely rare manifestations of tuberculosis occurring in a patient, ie, lichen scrofulosorum and ITP. Aberrant immune response may be the underlying pathophysiology for the occurrence of both these manifestations, hypersensitivity for lichen scrofulosorum and cytotoxic antibodies directed against platelets for ITP. Vineet K. Surana, MB BS Ankur Singh, MD Seema Kapoor, MD Department of Pediatrics Maulana Azad Medical College and associated Lok Nayak Hospital New Delhi, India