Publish date: Posted on
Last updated: November 27, 2024
Keywords #
- transient neonatal pustular melanosis
- TNPM
- erythema toxicum neonatorum
Diagnosis #
Transient neonatal pustular melanosis (TNPM) is a rare benign vesiculopustular eruption seen in all ethnic groups, but mostly in full-term dark-skinned infants. It is typically present at birth. The pustules seen in this condition are sterile and typically rupture after a few days, leaving behind residual hyperpigmentation that persists for several months [1]. Infants with this condition are otherwise healthy, and the condition resolves spontaneously without treatment.
Key Concepts #
- Transient neonatal pustular melanosis is an idiopathic pustular eruption that occurs in infants.
- It is recognized as a condition with significant overlap with erythema toxicum neonatorum [3].
- The etiology is unknown and no familial predisposition to this condition has been identified [5].
- It is characterized by small pustules on a non-erythematous base, usually noted at birth or during the first day of life.
- The lesions progress through stages and rupture within 2-3 days, leaving hyperpigmented macules with surrounding scaly collarettes (thin rings of scale) that fade within weeks to months [2].
- The condition is benign and requires no treatment.
Epidemiology #
Overall, this condition is rare, occurring in less than 5% of neonates [3]. It occurs in approximately 0.2% of Caucasian infants and 4.4% of black infants [2]. Full term infants are more likely to have TNPM than are preterm infants [4]. This condition is oftentimes misdiagnosed as one of a handful of more serious conditions, leading to unnecessary antibiotic use and hospital admissions [5].
Clinical Features #
- TNPM presents as 1-3 mm flaccid, superficial, fragile pustules with no surrounding erythema [1].
- The lesions are usually located over the chin, neck, forehead, back, and buttocks, and sometimes over the palms and soles.
- The pustules rupture easily and leave behind brown macules with surrounding rings of scaly skin.
- The macules are typically gone by the time the infant is 3 months old [4].
Differential Diagnoses #
- Erythema toxicum
- Neonatal varicella
- Neonatal HSV
- Neonatal acne
- Neonatal bullous impetigo
Diagnostic Workup #
No diagnostic workup is indicated for TNPM, as it is a clinical diagnosis.
Microscopic examination of the contents of a pustule, if performed, would demonstrate numerous neutrophils with few eosinophils. This is in contrast with ETN, in which the pustules contain numerous eosinophils [3]. If bacterial culture is performed, no organisms are seen [1].
Treatment #
No treatment is indicated, as the condition is benign and self-resolves.
Slide Viewer #
https://utahderm.med.utah.edu/image-viewer/References #
- Ghosh, S. Neonatal pustular dermatosis: An overview. Indian Journal of Dermatology. 2015; 60 (2): 211.
- Reginatto FP, Muller FM, Peruzzo J, Cestari TF. Epidemiology and Predisposing Factors for Erythema Toxicum Neonatorum and Transient Neonatal Pustular: A Multicenter Study. Pediatric Dermatology. 2017; 34 (4): 422-426.
- Michl C. Sterile transient neonatal pustulosis- an overlap between transient neonatal pustular melanosis and erythema toxicum neonatorum. Journal of the German Society of Dermatology. 2019; 17(7): 731-732.
- Hodgkins F. Transient Neonatal Pustular Melanosis. The Gale Encyclopedia of Dermatology, edited by Lisa Kumar. 2017; Volume 2: pp. 742-743.
- Obu, D et. al. Transient neonatal pustular melanosis: A possible cause of antibiotic misuse in neonates. Nigerian Journal of Medicine. 2020; 29 (3): 511.
