A 49-year-old male patient, a known case of ulcerative colitis on prophylactic sulfasalazine since 10 years, presented to us with two nontraumatic, painful, expanding ulcers; one each over anterior and anterolateral aspect of the left leg since 2 months. These lesions started as small follicular pustules that evolved into ulcers involving most of the pretibial region. Two months preceding the onset of these lesions, he also had an ongoing history of pain in the right hip which worsened on exertion.
Two years back he had similar lesions, one over the dorsal aspect of right feet and two over the back that resolved with cribriform scarring. During this period he had severe left-sided hip pain with complaints of burning micturition and increased urinary frequency, and was diagnosed with disseminated tuberculosis as documented in the MRI and urinary PCR reports. He was, thereby, put on antituberculous therapy (ATT), DOTS Category 1 which he abruptly stopped after 2 months of intensive phase. His physical condition was uneventful, until the preceding 2 months of his presentation to us.
Examination revealed two ulcers of sizes 10 x 8 cm and 3 x 2 cm, each with a purulent base and violaceous, undermined edges over the anterior and anterolateral aspect of left lower leg [Figures 1 and 2]. Investigations showed an elevated ESR, with a negative Mantoux test. Owing to his past history and present complaint, magnetic resonance imaging of bilateral hip was done that revealed altered signal around the left sacroiliac joint [Figure 3] and a small collection adjacent to right ischial tuberosity with altered signal within [Figure 4], suggestive of an infective etiology. Urinary PCR was negative for Mycobacterium tuberculosis. X-ray lumbosacral spine appeared normal and test for HLA B27 was negative. Cytological examination of the biopsy taken from the edge of the ulcer revealed normal epidermis with dermis showing perivascular lymphocytic infiltration with endothelial swelling and focal neutrophilic abscess [Figures 5 and 6], consistent with pyoderma gangrenosum. Patient was promptly started on ATT, DOTS Category 2 owing to his defaulter status, with resultant improvement in his lesions. After 1 month of starting the ATT he subsequently received two pulses of dexamethasone cyclophosphamide with intervening low-dose cyclophosphamide. Daily dressings were done until complete healing occurred.