Halo Nevus

Key Points

Caused by an autoimmune response to existing moles, such that the mole is often eliminated
Consists of paling skin surrounding a mole, which may start to fade away, leaving an area of depigmentation, or white or light colored skin.

Halo moles are a skin condition in which existing moles are targeted by the immune system for destruction. Initially, a small area of skin around the mole pales. As the condition progresses, the mole itself may become less pigmented and eventually fade away. The area of pale skin left in the affected area, which is generally round or oval in shape, persists for some time, then returns to normal coloring. This process may take up to several years. It occurs most commonly on the trunk, though infrequently may appear on the limbs or head. The affected moles are rarely malignant.

Halo moles are caused when the immune system targets existing moles for destruction. It is unknown what causes this response, but sunburn, and even the presence of malignant melanoma have been known to trigger it. Halo moles are typically seen in children or young adults, but may occur in and age or gender group.

Differential Diagnosis (Other conditions with similar appearance)
Atypical Mole
Molluscum contagiosum
Basal cell carcinoma
Pityriasis lichenoides
Lichen Planus
Spitz nevus
Lichen Sclerosus et Atrophicus
Vitiligo
Malignant Melanoma

Diagnosis
Key Points
Initial diagnosis based on appearance of the affected mole
Mole may be biopsied to confirm diagnosis and rule out other similar appearing conditions

Halo moles are initially diagnosed based on the appearance of the affected mole. A Biopsy may be performed to confirm the diagnosis and rule out other, similar appearing conditions. Similar symptoms may be seen in Vitiligo and Melanoma, so proper diagnosis is important.

Treatment
Treatment is not generally required, as the condition is self-resolving
Full skin examination is recommended to ensure that other skin conditions are not extant
*Sunscreen should be used to protect the affected area
OTC Options: Sunscreen

Halo moles typically resolve themselves after a period of time, so treatment may not be necessary. A biopsy should be considered if the mole displays other unusual signs, because the halo phenomenon can be due to the immune system recognizing a Melanoma. Health care professionals may perform a full skin examination to ensure no other associated skin conditions exist. Sunscreen should be used to protect the affected area from sunburn, as the skin is missing melanin, which protects it from sun exposure.