Halo Nevus - Causes, Symptoms and Treatment

Definition

A halo nevus is a mole that is surrounded by round, symmetric depigmented area or a halo. The halo itself has sharply demarcated borders. There are no melanocytes, or cells that make melanin, in the halo area. Halo nevi develop spontaneously, usually in adolescence, on the trunk, but sometimes on the palms and soles. A person can have just one halo nevus or several halo nevi. Halo nevi occur in skin of all colors and in people of all racial and ethnic backgrounds. As a halo nevus develops, an area of depigmentation appears around the mole over a period of days to weeks. The condition is believed to be common, even though only 300 cases have been reported. Estimated incidence is 1%, with occurrences probably equal in boys and girls. Halo nevi are generally first reported in the late teenage years, but they have also been reported in newborns and the elderly. They are occasionally reported in members of the same family.

Causes

1. A halo nevus occurs when the immune cells which fight against the infections rather than saving our body attack a mole. The reason of attack is unknown.
2. The people with vitiligo are found more likely to cause halo nevus.
3. The person having malignant melanoma is also more likely to cause halo nevus.
4. Sometimes halo moles are triggered by sunburn which damages the mole and causes it to be recognized by the body as foreign.
5. Atypical moles are more common on people with halo nevi. Atypical moles are thought to have an increased risk of turning cancerous.

Symptoms

1. Patients with halo nevi are usually asymptomatic. The central nevus may or may not involute with time. Repigmentation often takes place over months or years; however, it does not always occur.
2. Halo nevi are usually single but may be multiple.
3. Inflammation occurs with crusting in the depigmented zone of a halo nevus occasionally.
4. They can develop anywhere on the body but are seen most frequently on the trunk.
5. The appearance of one or more uniformly colored, evenly shaped, oval or round nevi central with even peripheral margins of hypopigmentation.

Treatment

1. Halo nevi are considered harmless and self-limiting. Hence no treatment is required generally.
2. A yearly complete skin exam is recommended for those with halo nevi or a single halo nevus to make sure there are no atypical moles or malignant melanoma on the skin.
3. If the central lesion is problematic in appearance, however, removal of the mole with its surrounding halo is recommended.
4. Sunscreen should be applied to all the skin during summer to prevent sunburn. The white skin of a halo nevus will burn particularly easily in the sun because it is missing protective melanin pigment.
5. In severe cases where the moles are likely to grow strangely or changing colors then surgery may be done. Surgery is very rare in case of halo nevus.
6. Laser treatment may lighten areas of the nevus and improve its appearance, but it is not recommended because it doesn't remove the deeper pigment cells where malignant changes occur.