A Prospective Cross-sectional Study to Determine the Bacteriological Profile and Antibiotic Sensitivity Patterns of Cutaneous Lesions in Immunobullous Disorders

Background: The immune bullous disorders are characterized by a pathogenic immune response against the structural proteins of keratinocytes or dermoepidermal basement membrane zone. Septicemia and bacterial skin infections are the main causes of mortality and morbidity in immunobullous disorders. Aim: To study the bacteriological profile of active cutaneous lesions present in autoimmunobullous disorders and their antibiotic sensitivity patterns. Materials and Methods: A cross-sectional study conducted from September 2022 to June 2024. Cases confirmed by biopsy and/or immunofluorescence with clinically active cutaneous lesions were included for culture and sensitivity. Results: Out of the 85 patients diagnosed with autoimmunobullous disorders, 48 (56.5%), 18 (21.2%), and 15 (17.6%) had pemphigus vulgaris (PV), pemphigus foliaceus, and bullous pemphigoid (BP), respectively. The study included patients ranging in age from 0 to 85 years old. The most commonly affected groups were young adults in the 20–29 years’ age range and older patients in the 60–69 age range, with a bimodal distribution. Females outnumbered males. The percentage of nonsterile swabs on pus culture and sensitivity was 47.1%, which was lower than the percentage on sterile swabs (54.5%). The most common organism isolated was Staphylococcus aureus (SA) (92.25%) in which 37.5% was resistant to methicillin, followed by Pseudomonas aeruginosa (5%) and Klebsiella pneumoniae (2.5%). Pemphigus foliaceus patients (55%) had the highest rate of bacterial growth, followed by PV (39.86%) and BP patients (33.33%). The majority of BP cases (66.67%) had sterile pus cultures, which were subsequently followed by pemphigus foliaceus (45%) and PV (63.14%). SA was 100% sensitive to antibiotics teicoplanin, linezolid, nitrofurantoin, vancomycin, tigecycline, followed by trimethoprim/sulfamethoxazole (94.44%), rifampicin (88.89%), oxacillin (88.89%), daptomycin (88.89%), and azithromycin (77.27%). The most resistant antibiotic to SA was benzyl penicillin (83.33%), which was followed by erythromycin (38.88%), ciprofloxacin (77.77%), and levofloxacin (61.11%). The sensitivity pattern for methicillin-resitant SA (MRSA) to vancomycin was 100% followed by tetracycline (93.33%), tigecycline (93.33%), trimethoprim/sulfamethoxazole (93.33%), and nitrofurantoin (86.67%). The antibiotics with the highest MRSA resistance were erythromycin (73.88%), ciprofloxacin (86.777%), levofloxacin (86.67%), and benzyl penicillin (100%). Conclusion: In 45% of the cases, bacterial growth was seen, and SA was the most commonly isolated organism. Secondary cutaneous bacterial infection was more common in pemphigus foliaceus. The most resistant antibiotic was benzyl penicillin, while vancomycin was 100% sensitive to MRSA.