Dermatologic reaction following intramuscular injection
Abstract:
Background: Nicolau syndrome (NS) is a rare iatrogenic dermatologic reaction following intramuscular (IM) injections that is not well understood. It is especially uncommon in the extremely preterm neonatal population with this case being the first to document additional vascular findings.
Clinical findings: A 24-week female infant weighing 623 g presented with a large, violaceous oval patch measuring 4.5 cm × 2.5 cm with an erythematous border on the left lateral thigh accompanied by dusky toes shortly after receiving routine IM injection of vitamin K.
Primary diagnosis: Once differential diagnoses were ruled out, an investigation of the IM vitamin K injection method and proximity of injection to initial onset of symptoms showed administration to be the cause. After review of the literature, NS was determined to be the most plausible diagnosis.
Interventions: To restore perfusion to the toes, the left leg was elevated, and a warm compress was applied to the contralateral foot. Bacitracin was administered topically, and the lesion was monitored over time.
Outcomes: The lesion healed, leaving a linear scar circumscribed by a hypopigmented patch without secondary complications.
Practice recommendations: As this is an iatrogenic event, development of standardized practice guidelines for IM injections in premature infants is recommended, especially in the extremely preterm and low birth-weight population. Vitamin K should continue to be administered through IM route as recommended by the American Academy of Pediatrics.
Reference:
Miller AR, Whyte NC, Abebe EW. Nicolau Syndrome in an Extremely Premature Neonate: A Case Report. Adv Neonatal Care. 2026 Jul 13. doi: 10.1097/ANC.0000000000001365. Epub ahead of print. PMID: 42461980.