A Rare Cause of Nonhealing Ulcer in an Immunocompetent Person.

Abstract

Sir, A 58-year-old lady, a homemaker, presented with a nonhealing ulcer over the right lower limb for 1.5 months. There was a history of trauma following which she had developed the wound. The patient had received oral antibiotics (a combination of amoxicillin–clavulanic acid and metronidazole), but no clinical improvement was observed. There was no history suggestive of diabetes mellitus, peripheral vascular disease, varicose veins, or recurrent infections in past. There was no significant history of hospitalization before this episode. On examination, the patient was hemodynamically stable, all peripheral pulses were palpable. A 3 cm × 3 cm ulcer with sloping edges, red granulation tissue with purulent discharge on the right lateral malleolus (Gaiter's area), surrounding edema, erythema, and hyperpigmentation were seen [Figure 1].Figure 1: A 3 cm × 3 cm ulcer with sloping edges, red granulation tissue with purulent discharge on the right lateral malleolus, with surrounding edema, erythema, and pigmentationThe patient was evaluated for a nonhealing ulcer. Complete blood count was suggestive of elevated total lymphocyte count with neutrophilic predominance, with no atypical cells on the peripheral blood smear. Erythrocyte sedimentation rate 67 mm/h. Serology for HIV, HBsAg, anti-HCV antibodies was negative, and HbA1c was 5.1%. The blood culture and urine culture were sterile. Among radiological studies, a chest radiograph was normal, and the venous and arterial Dopplers of the lower limb were normal. Two-dimensional echocardiography revealed a normal study. Pus samples for acid-fast bacillus smear and culture, KOH mount, and fungal culture were also negative. Magnetic resonance imaging of the lower limb was suggestive of soft-tissue swelling and osteomyelitis of the fibular bone. Levels of immunoglobulins A, immunoglobulins M, and immunoglobulins G were 92 mg/dl, 206 mg/dl, and 976 mg/dl, respectively. Her CD4 count was 789 cells/uL. Gram stain and culture sensitivity of pus showed heavy growth of Stenotrophomonas maltophilia with sensitivity to ceftazidime, cefepime, aztreonam, and colistin. The patient was started on injection colistin, which she received for 21 days along with supportive measures. By day 14, there was a gross improvement with complete healing of the wound in a month. S. maltophilia is a gram-negative bacillus with intrinsic drug resistance to various antimicrobials including beta-lactams, fluoroquinolones, and aminoglycosides.[1] It is known to cause a variety of infections in immunocompromised individuals, especially candidates with hematopoietic stem-cell transplantation, receiving cytotoxic chemotherapy, and those with neutropenia.[1] It commonly causes infection in immunodeficient individuals; however, in recent times, a surge in the number of cases of immunocompetent individuals developing skin and soft-tissue infection has been observed. Our patient acquired infection of S. maltophilia probably from the environment despite being immunocompetent.[2] Since the patient showed a dramatic response to culture-guided antibiotics with complete healing of the wound, the possibility of colonization was less likely. Therefore, we conclude that a possibility of S. maltophilia should also be kept as a possibility in cases of nonhealing ulcers even in immunocompetent individuals. Declaration of patient consent The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient has given her consent for her images and other clinical information to be reported in the journal. The patient understands that her name and initials will not be published and due efforts will be made to conceal identity, but anonymity cannot be guaranteed. Research quality and ethics statement The authors followed applicable EQUATOR Network (http://www.equator-network.org/) guidelines, notably the CARE guideline, during the conduct of this report. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.