Angiolymphoid hyperplasia with eosinophilia - Hair and Scalp
ALHE typically presents with skin-colored, pink, dull red, or brown papules or nodules on the head and neck. Approximately 50% of patients have multiple lesions that tend to be clustered particularly around the ears, forehead, and scalp. Other less common locations include the genitals (vulva or penis), trunk, and distal extremities. Most lesions are located dermally but ALHE can involve the subcutis and deeper soft tissues.
ALHE may also involve extracutaneous sites such as bone, colon, parotid gland, mouth, and orbit. Peripheral eosinophilia may be present in a subset of patients.
ALHE may present with pain, pruritus, or spontaneous bleeding, or it may be asymptomatic.
The underlying pathogenesis is unknown. There is no consensus as to whether the condition is reactive, possibly in response to trauma, or neoplastic.
Of note, ALHE and Kimura disease, once thought to be disease variants, are now recognized to be separate, distinct diseases with specific clinical and histologic features.
D18.01 – Hemangioma of skin and subcutaneous tissue
125574005 – Angiolymphoid hyperplasia with eosinophilia
Differential Diagnosis & Pitfalls
- Sarcoidosis – Papules and plaques, often with a reddish-brown coloration, favor the face, lips, neck, trunk, and upper extremities. They tend to be fairly symmetric. Lesions usually have an "apple jelly" yellow-brown color upon diascopy (where a lesion is blanched, to diminish erythema, by applying pressure with a glass slide or other transparent implement).
- Cylindromas – Early lesions may present as erythematous papules on the head and neck; they usually grow and can coalesce into the "turban tumor."
- Scleromyxedema – 2- to 3-mm waxy firm papules on head and neck, dorsal hands, and forearms. Distribution is symmetric, with papules often in linear array.
- Kimura disease