| Disease | Clinical clues | Confirming diagnostic steps |
| Nonsyndromic congenital ichthyoses |
| Nonbullous ichthyosiform erythroderma | - Collodion membrane
- Ectropium, eclabium
- Lamellar scaling
| - Gene panel analysis (TGM1, ALOX12B, ALOXE3, ABCA12, CYP4F22, NIPAL4, SDR9C7, CERS3, PNPLA1, SLC27A4)
|
| Epidermolytic ichthyosis | - Skin blistering
- Palmoplantar hyperkeratosis
| - Skin biopsy
- Targeted sequencing KRT1, KRT10 gene
|
| Peeling skin syndrome type B | - Generalized superficial skin peeling
- Severe pruritus
- Food allergy/anaphylaxis
| - Skin biopsy
- Targeted sequencing CDSN gene
|
| Syndromic congenital ichthyoses |
| Sjögren-Larsson syndrome | - Yellowish hyperkeratosis
- Psychomotor retardation
- Spastic di-/tetraplegia
| - Comprehensive neuropediatric evaluation
- Targeted sequencing ALDH3A2 gene
|
| Chanarin-Dorfman syndrome | - Collodion membrane
- Hepatopathy
| - Granulocyte microscopy
- Targeted sequencing CGI85 (ABDH5) gene
|
| Netherton syndrome | - Severe inflammatory erythroderma
- Debilitating pruritus
- Hair shaft anomalies
| - Hair shaft dermoscopy
- Immunohistochemistry
- Targeted sequencing SPINK5 gene
|
| Infections |
| Staphylococcal scalded skin syndrome | - Omphalitis, impetigo, etc
- Erythema beginning in skin folds
- Superficial skin exfoliation
| - Skin biopsy
- PCR screening of toxin genes in S. aureus strains
|
| Congenital cutaneous candidiasis | - Postpartal pustular rash
- Paronychia
| |
| Benign erythematous skin disorders |
| Seborrheic dermatitis | - Early onset before 2 months of life
- Involvement of flexural areas, "cradle cap"
| - Clinical diagnosis
- Skin biopsy in clinically atypical cases
|
| Atopic dermatitis | - Onset ≥3 months of life
- Diaper area usually not involved
|
| Infantile psoriasis | - Sharply delineated plaques
- Diaper area typically involved
|
| Infantile pityriasis rubra pilaris | - Large, confluent plaques
- Islands of spared skin ("nappes claires")
|
| PID |
| Omenn syndrome | - Severe failure to thrive
- Recurrent atypical/severe infections
- Hepatosplenomegaly, lymphadenopathy
| - Lymphocyte phenotyping
- Gene panel analysis
- Evaluation in PID referral center
|
| Graft-versus-host disease | - Severe failure to thrive
- Recurrent atypical/severe infections
- Alopecia
| - Lymphocyte phenotyping
- Chimerism analysis
- Evaluation in PID referral center
|
| Wiskott-Aldrich syndrome | - Eczematous dermatitis
- Petechiae, ecchymosis
- Thrombocytopenia
| - Peripheral blood count
- Targeted sequencing of WAS gene
- Evaluation in PID referral center
|
| IPEX syndrome | - Failure to thrive
- Diabetes, enteropathy
| - Endocrinologic and GIT workup
- Targeted sequencing of FOXP3 gene
- Evaluation in PID referral center
|
| Inborn errors of metabolism |
| HCS deficiency | - Lethargy, seizures
- Metabolic acidosis
| - Newborn screening, blood gas analysis
- Urine organic and amino acid analysis
- HCS activity in leukocytes, genetic testing
|
| Methylmalonic acidemia | - Neurologic symptoms, respiratory distress
- Metabolic acidosis
| - Newborn screening, blood gas analysis
- Urine organic/amino acid analysis, genetic testing
|
