Serratia marcescens Colonization Causing Pink Breast Milk and Pink Diapers: A Case Report and Literature Review

Serratia marcescens is an opportunistic pathogen and common cause of infectious outbreaks in pediatric units, leading to both significant morbidity and mortality in immunocompromised hosts. Environmental and some clinical strains may produce a characteristic red pigment, prodigiosin. Colonization can hence turn breast milk and fecally-soiled diapers pink, which can lead otherwise unaffected patients to present to their physicians and also interrupt breastfeeding. No clear guidance exists regarding the outpatient management of breastfeeding mothers and infants colonized with S. marcescens.

Our aim was to understand the significance of pigment-producing S. marcescens colonization of breast milk and stools in healthy infants in the community setting. We describe the case of a healthy 9-week-old infant presenting with pink soiled diapers secondary to S. marcescens colonization and systematically review previously reported cases of infants diagnosed with pink diapers or milk published in PubMed between 1958 and 2017.

Six publications describing seven additional mother-infant cases were selected for inclusion. In all, 8 mother-infant groups of colonization were reviewed, involving 10 infants (there were 2 sets of twins). Good clinical outcomes were reported in all cases regardless of whether antibiotic treatment was prescribed.

Providers evaluating mother-infant dyads with S. marcescens colonization causing pink milk or pink infant soiled diapers should assess for manifestations of systemic infection. In the absence of evidence of clinical infection, expectant management is appropriate and continued breastfeeding can be supported.