MRSA in Dermatology Inpatients With a Vesiculobullous Disorder

Comment

In this 1-year study, we tested and followed 43 patients with autoimmune and drug-induced vesiculobullous disorders. Vesiculobullous disorders in dermatology inpatients are a cause of great concern. When lesions rupture, they leave behind a large area of erosion that forms a nidus of bacterial colonization; often, these bacteria cause severe infection, including septicemia, and result in death.⁵ Moreover, autoimmune bullous disorders usually require a prolonged hospital stay and powerful immunosuppressive drugs, which contributes to bacterial infection, especially MRSA.⁶

The age of patients in this study ranged from 13 to 80 years; most patients were in the 6th decade, a pattern seen in studies worldwide.⁵ In a study by Kanwar and De,⁷ however, most cases were aged 20 to 40 years.⁷ In our study, there was a female preponderance (male to female ratio of 0.65 to 1).

Studies have shown that the duration of illness in vesiculobullous disorder is directly associated with MRSA infection. However, in our study with MRSA detected in 14 patients, most patients had a duration of illness less than 1 year (statistically insignificant [P>.05]), a finding similar to Shafi et al.⁸

The symptomatic nature of these diseases, their unsightly appearance, and mucous-membrane involvement of vesiculobullous disorders prompts these patients to present to the hospital early. However, a prolonged hospital stay by patients with an autoimmune vesiculobullous disorders sets the stage for MRSA colonization.

In this study, diabetes mellitus (DM) was seen in 15 patients (34.9%); 5 of them had MRSA infection (statistically insignificant [P>.05]). Diabetes mellitus contributing to sepsis and MRSA infection, which in turn contributes to morbidity and mortality, has been well-documented.^2,4,9

Methicillin-resistant S aureus in this study was isolated most often from blisters and erosions. Vesiculobullous disorders and drug reactions (eg, Stevens-Johnson syndrome, TEN) are characterized by blisters that rupture to form erosions and crusting, which form fissures in the epidermal barrier function that are nidi for colonization by microbes, especially S aureus and MRSA in particular; later, these bacteria can enter dermal vessels and then the bloodstream, leading to septicemia.¹⁰

The prevalence of MRSA in this study was 32.6% (14/43), which is high compared to other studies.^2-4 Pemphigus vulgaris was the most common disorder infected by MRSA in this study (57.1% [8/14] of MRSA isolates)(Table 1), a finding that reveals that the incidence of MRSA is high among staphylococcal isolates in vesiculobullous disorders. However, the high incidence of MRSA in this study could be a reflection of the number of patients with a severe and chronic vesiculobullous disorder, such as PV, and serious drug reactions such as TEN referred to our tertiary-care center, where we get a large number of patients affected by autoimmune and drug-induced vesiculobullous disorders. Similar findings have been reported by Stryjewski et al.¹¹

A high prevalence of MRSA in a dermatology unit has grave consequences, contributing to morbidity and mortality in particular among patients with a vesiculobullous disorder. Immunosuppressive therapy and comorbidities such as DM contribute to MRSA colonization in vesiculobullous disorders.¹² Overcrowding and poor sterilization techniques in public hospitals in India may contribute to the high prevalence of MRSA seen in hospital units.

Patients with a vesiculobullous disorder who are chronic nasal carriers of MRSA are at risk for cutaneous MRSA infection, which in turn can lead to MRSA septicemia and an elevated risk of death. In this study, however, a nasal swab was positive for MRSA in only 7 patients. One patient with MRSA colonization died, which was statistically insignificant (P=1).

In this study, all MRSA strains (100%) were resistant to first-line antibiotics, such as oxacillin, cloxacillin, and cefoxitin; all strains were susceptible to vancomycin and linezolid. This finding is similar to prior studies.^13,14 A distinctive finding in this study is that 34 (79.1%) of MRSA isolates were susceptible to amikacin. This finding has practical significance. Amikacin, an inexpensive antibiotic that is readily available in most units, can be used to treat MRSA infection in resource-poor settings where vancomycin and linezolid are unavailable.

Conclusion

Our study shows that MRSA is becoming the prominent pathogen in nosocomial infections, especially in bedridden patients, which has grave implications. The use of a prophylactic S aureus conjugate vaccine in patients with a chronic vesiculobullous disorder might be justified in the future.¹⁵ We found a high prevalence (32.6%) of MRSA in vesiculobullous disorders, no relationship between DM and MRSA colonization, PV was the most common disorder complicated by MRSA, no relationship between nasal colonization and MRSA infection, no relationship between death during the study period and MRSA infection, 100% of MRSA strains were susceptible to vancomycin and linezolid, and 79.1% of MRSA strains were susceptible to amikacin.