Examkin

Question

Difficulty: HardNeonatal Disorders

While evaluating a cohort of infants on the postnatal ward, a pediatrician encounters several characteristic dermatologic presentations. Match the specific clinical and cytological findings (1-4) with their appropriate benign neonatal dermatosis diagnosis.

  • A widespread eruption of 1- to 3-mm yellowish papules on an erythematous base, explicitly sparing the palms and soles; cytological examination of the exudate shows a predominance of eosinophils.Erythema toxicum neonatorum
  • Fragile vesiculopustules present immediately at delivery that rapidly rupture, evolving into hyperpigmented macules with a collarette of scale; microscopic examination of the fluid reveals abundant polymorphonuclear leukocytes.Transient neonatal pustular melanosis
  • A self-limited eruption consisting of monomorphic inflammatory papules and pustules confined to the face and scalp, notably absent of comedones, mediated by an inflammatory reaction to Malassezia species.Neonatal cephalic pustulosis
  • Superficial epidermal inclusion cysts appearing as 1- to 2-mm pearly white papules clustered primarily on the nasal bridge, representing trapped keratinized material within the pilosebaceous units.Milia

Answer

The correct matches pair the eosinophilic rash that spares palms/soles with Erythema toxicum neonatorum; the neutrophilic rash present at birth leaving pigmented macules with Transient neonatal pustular melanosis; the Malassezia-driven rash without comedones with Neonatal cephalic pustulosis; and the keratin retention cysts with Milia.
Each benign neonatal dermatosis has pathognomonic features: Erythema toxicum neonatorum is defined by an eosinophilic infiltrate and palmar/plantar sparing. Transient neonatal pustular melanosis is present at birth, leaves hyperpigmented macules, and shows a neutrophilic infiltrate. Neonatal cephalic pustulosis is driven by Malassezia and lacks comedones. Milia are distinct keratinous inclusion cysts.

Step-by-Step Solution

1
Analyze the cellular infiltrate and anatomical distribution in the first description.
The presence of eosinophils and the specific sparing of the palms and soles identify erythema toxicum neonatorum.
Microscopic analysis of pustule fluid is the definitive way to differentiate this rash from similar appearing eruptions; eosinophils are pathognomonic here.
2
Evaluate the timing, progression, and cytology of the second description.
Lesions present strictly at delivery that leave hyperpigmented macules and contain neutrophils identify transient neonatal pustular melanosis.
Unlike erythema toxicum, this condition is present exactly at birth, involves neutrophils, and leaves a temporary residual pigmentation.
3
Identify the key negative clinical finding and etiology in the third description.
The absence of comedones combined with a facial distribution and Malassezia etiology distinguishes neonatal cephalic pustulosis.
True acne requires comedones; the neonatal variant is an inflammatory yeast reaction rather than a true acneiform disorder.
4
Assess the structural nature of the lesions in the fourth description.
Keratin-filled inclusion cysts clustered on the nose describe milia.
These are non-inflammatory anatomical retention cysts, differentiating them completely from the inflammatory pustular eruptions.

Key Concept

Differentiating benign neonatal skin lesions based on lesion morphology, age of onset, presence of comedones, and specific cytological findings (eosinophils vs. neutrophils).
Rate this question

Topics

Neonatal Disorders

More questions from this topic