Polymyxin B-Induced Diffuse Cutaneous Hyperpigmentation.

Polymyxin B is a polypeptide-antibiotic, primarily used for resistant Gram-negative infections, first obtained from bacterium in the late 1940s. Antibiotic spectrum are restricted to mainly gram negative bacterias like ; and particularly organisms like and which are extremely potent to acquire antibiotic resistance. Side effects include neurotoxicity and acute renal tubular necrosis.