High-dose tigecycline-induced cutaneous hyperpigmentation

Urinary tract infection (UTI) is a common infectious ailment with significant mortality, morbidity and overall financial burden. This case report describes an elderly diabetic lady with chronic kidney disease and other multiple comorbidities who during the hospital stay, develops a nosocomial UTI with multidrug-resistant (MDR) Enterococcus faecium (vancomycin-resistant Enterococcus), intermediately sensitive to daptomycin and tigecycline. Accordingly, tigecycline 100 mg intravenous (iv) twice daily and daptomycin 350 mg iv every alternate day was initiated. 3 days after initiation, a diffuse darkening of skin and generalised blackish pigmentation was noted. The patient showed clinical improvement with respect to the UTI; hence, the ongoing treatment was continued till the improvement of procalcitonin levels, irrespective of the observed adverse drug reaction (ADR), which was deemed to be non-serious. Post stoppage of tigecycline, the patient showed betterment of skin tone by 1 month without any medical intervention. Concerning temporal relationship and causality assessment, diffuse skin hyperpigmentation is thus a probable ADR of tigecycline. Existing literature does not document much about skin hyperpigmentation as ADR of tigecycline. With the increasing incidence of infections by MDR organisms and the greater use of the rReserved category of antibiotics, high-dose tigecycline is thought to become increasingly popular in the days to come due to its wide antimicrobial spectrum. However, cutaneous hyperpigmentation is a probable complication of such a therapy, especially in the presence of other contributing factors. Knowledge of this ADR and its further case reporting may pave the way to better patient outcome communications, lesser psychological burdens and minimising litigations.