Pursuit of the Pink Diaper: A Medical Mystery
What would cause a diaper to turn pink after sitting overnight in the diaper pail? Read this case closely for the clues.
An 8-wk-old infant is rushed to PACC
after his mother finds a diaper that has become pink while sitting in the diaper pail. Hx: born 6 weeks prematurely, treated for long course of neonatal pneumonia.
At home, infant was doing well, breast feeding appropriately
but a pinkish-red diaper, discarded after stool had been removed, unnerved the mother.
Physical exam was normal
so the following tests were ordered: CBC; catheterized urine for UA/culture; culture of still moist diaper; rectal culture.
Lab results
CBC, normal; UA, normal⦠no hematuria on dip stick, no RBCs viewed microscopically; other culture results, pending.
Clinical suspicion pointed to
a non-urgent cause but child was hospitalized pending results of all tests ordered.
Summary of current knowledge:
infant was significantly ill at birth, treated extensively with antibiotics; entirely well upon d/c; breast feeding/no nipple fissures; diaper undeniably pink.
Differential diagnosis:
Medication-induced coloration; foods via maternal breast milk; intravascular hemolysis; other medical condition (eg porphyria); myoglobinuria; red diaper syndrome from
Serratia marcesans
Microbiology lab
showed us the urine culture plate and the rectal swab plate.
Culture revealed the gram negative organism known as Serratia marcescens.
Diagnosis: Red diaper syndrome
caused by
Serratia marcescens.
A brief preface to the case from the author: Like many Navy physicians, even though I was a subspecialist in adolescent medicine, I had call or was asked to help out several times a month in the pediatric acute care clinic (PACC). I did not mind that much as I had been a general pediatrician for 13 years when I finally decided to do my subspecialty. I wavered between pediatric dermatology and adolescent medicine, but adolescent medicine finally won out.I trained at a time when we did much of our own lab work, including microbiology, and I had become quite adept in that field of study. I felt this provided me with a more holistic approach to solving medical mysteries.The case you'll follow above, I think, will prove my point. Resources are below, but read the case to the end, first.   Resources Mahlen SD. Serratia infections: from military experiments to current practice. Clin Microbiol Rev. 2011;24:755- 791.Yu VL. Serratia marcescens-historical perspective and clinical review. N Engl J Med. 1979; 300:887-893.For additional reading please see references cited in the case "A Tale of Two Urines."