Situations where encountered include:
(1) radiation therapy for brain tumor, including proton beam therapy
(2) radiation therapy of other head and neck tumors with inclusion of hair-baring area in the radiation field
(3) procedure under fluoroscopic guidance
(4) embolization of an intracranial artery or arteriovenous malformation
(5) nuclear event with whole-body exposure
The severity of the alopecia is dose-dependent. The alopecia is often temporary if the radiation exposure is mild.
The area of alopecia may be localized if only a portion of the scalp was exposed. Diffuse alopecia can occur if a large area was included within the radiation field.
Trichoscopic features:
(1) white patches
(2) decreased hair-shaft caliber
Some cases of alopecia respond to minoxidil therapy.
Differential diagnosis:
(1) chemotherapy-associated chemotherapy
(2) other causes of alopecia
