History Taking for Aplasia Cutis Congenita
When evaluating a patient with suspected aplasia cutis congenita (ACC), focus your history on identifying the lesion characteristics, associated anomalies, family patterns, and potential teratogenic exposures to distinguish isolated benign ACC from cases requiring urgent intervention or those associated with serious syndromes.
Lesion Characteristics
- Location and extent: Document whether the defect is on the scalp (most common, particularly vertex/parietal region) versus trunk or extremities, as location guides evaluation for associated anomalies 1, 2
- Size of defect: Measure and record dimensions, as lesions >3 cm or extensive defects involving the entire crown/vertex carry higher risk of underlying skull defects and complications 3, 4
- Appearance at birth: Ask whether the lesion appeared as an ulcer, bullous lesion, atrophic scar, or membranous covering, as this helps differentiate ACC from other conditions 2, 5
- Single versus multiple lesions: Multiple lesions suggest different etiologies and may indicate syndromic associations 3, 5
Maternal and Pregnancy History
- Teratogenic exposures: Specifically inquire about maternal use of antithyroid drugs (methimazole, carbimazole), cocaine, heroin, alcohol during pregnancy, as these are established causes of ACC 3
- Intrauterine infections: Ask about varicella zoster virus or herpes simplex virus infection during pregnancy 3
- Medications during pregnancy: Document all medications, particularly those in first trimester 3
- Pregnancy complications: Ask about oligohydramnios, placental infarction, or twin pregnancy complications 2, 5
Family History
- Consanguinity: Document whether parents are related, as this may play a role in ACC development 6
- Family members with similar lesions: Ask specifically about siblings or other relatives with scalp defects at birth, as familial cases are well-documented 6, 3
- Pattern of inheritance: If positive family history exists, document whether autosomal dominant or recessive pattern is apparent 3, 5
Associated Anomalies and Syndromes
- Limb abnormalities: Ask about limb defects, particularly transverse terminal limb defects, as these suggest Adams-Oliver syndrome 3, 5
- Vascular malformations: Inquire about cutis marmorata telangiectatica congenita or other vascular lesions, which can be associated with ACC 3, 5
- Hemangiomas: Document presence or absence of hemangiomas, as these may be associated with certain ACC patterns 6, 2
- Other congenital defects: Ask about cardiac, renal, or other organ system abnormalities 2, 5
- Blistering skin: Inquire about fragile skin or blistering elsewhere on the body to evaluate for epidermolysis bullosa 5
Neurological Symptoms and Concerns
- Seizures or abnormal movements: Document any neurological symptoms, as ACC with skull defects may be associated with CNS malformations 4
- Bleeding from the lesion: Ask about any hemorrhage, as this indicates possible sagittal sinus exposure and represents a life-threatening emergency 3, 4
- Signs of infection: Document fever, purulent drainage, or surrounding erythema, as exposed dura or brain tissue carries high infection risk 3, 4
Clinical Pitfalls to Avoid
The critical distinction is between superficial ACC (benign, often self-resolving) and deep ACC with skull defects (20% of cases), which exposes the brain and sagittal sinus to fatal hemorrhage or infection 3. Midline scalp ACC that appears membranous or has a pulsatile quality should raise immediate concern for underlying skull defect and requires urgent imaging 1, 4. Do not confuse ACC with atretic encephalocele—the latter has a "hair collar" sign, underlying bony defect, and abnormal venous drainage patterns on imaging 1. Additionally, recurrent or persistent "ACC" in the same location, particularly in older patients, should prompt consideration of malignancy rather than congenital absence of skin 7.