Polymyxin B induced generalized skin hyperpigmentation in infants

Abstract

Polymyxin B is a polypeptide antibiotic derived from Bacillus polymyxa. It has bactericidal activity against aerobic gram negative bacteria including multidrug resistant Pseudomonas aeruginosa, Acinetobacter baumannii, Klebsiella pneumoniae and carbapenemase producing Escherichia coli. One of the common adverse reactions noted among infants receiving IV Polymyxin B was increased in skin pigmentation. In our literature search, there has been no report on Polymyxin B induced skin hyperpigmentation. We are reporting this additional adverse reaction noticed as the use of Polymyxin B is becoming prevalent. This is a prospective case study on the infants who have been treated with IV Polymyxin B due to multidrug resistant bacteria in Neonatal Intensive Care Unit (NICU), Sarawak General Hospital (SGH) from 2^nd February 2012 till 31^th July 2012. The skin tone changes were captured with a digital camera with same shooting mode from day 0 to at least day 14 of IV Polymyxin B and continued to be monitored until discharges. Data collection is done by studying on the skin tone from the photos captured of the recruited patients. All the 16 infants, their skin tone were progressively darkened throughout the treatment period. 8 infants recruited have their skin tone reverted to baseline colour averagely at 46 days post IV Polymyxin B treatment and 3 infants have their colour became fairer averagely at 34 days post IV Polymyxin B treatment. Remaining 5 infants had persistent hyperpigmentation upon discharged or deceased. Among the 5 infants who had persistent skin hyperpigmented, 1 of them died due to uncontrolled septicaemia 14 days after treatment completed and the remaining 4 had their skin fairer during subsequent clinic follow up. Reversible generalised cutaneous hyperpigmentation is a common complication noted in premature infants receiving polymyxin B. The mechanism of skin hyperpigmentation secondary to IV Polymyxin B is still unknown. Larger sample size is needed to prove the adverse reaction more evidently.