A halo nevus is a mole that is pink or brown surrounded by round, symmetric depigmented area, or a halo. Halo nevi are not dangerous or contagious, but they are sometimes a sign that is not good for the skin. A person can have just one halo nevus or several halo nevi. It is relatively common, occurring particularly in older children and teenagers. The trigger or cause of spontaneous pigment loss in a halo nevus is not known; however, pigment loss is the result of an immunologic process in which melanocytes are destroyed. Halo nevi are usually seen in young people. The mole portion tends to flatten and may disappear completely. The white area may stay if the mole disappears, or the normal skin color may return. This relatively common disorder occurs between the first and fifth decades of life, most frequently during late adolescence. Halo nevi can occur almost anywhere on the body, but most often appear on the trunk, especially the back. They are occasionally reported in members of the same family.
Halo nevi are benign. Morbidity is minimal and limited to cosmetic appearance. Because halo nevi are quite distinct in their presentation, diagnosis is obvious. Most halo nevi are seen with benign moles. Rarely, this phenomenon is seen around a malignant melanoma. If the central lesion appears atypical and suspicious, it should be removed and biopsied for microscopic evaluation. All the races are equally susceptible to suffer from halo nevus. It mostly occurs in children and the average age of onset is fifteen years. 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. Halo nevi are considered harmless and self-limiting and are not treated. If the central lesion is problematic in appearance, however, removal of the mole with its surrounding halo is recommended.
Causes of Halo nevus
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. The trigger of spontaneous pigment loss in a halo nevus is not known; however, pigment loss is the result of an immunologic process in which melanocytes are destroyed. Atypical moles are more common on people with halo nevi. Atypical moles are thought to have an increased risk of turning cancerous.
Common causes and risk factors of Halo nevus:
- Sunburn which damages the mole.
- A halo nevus occurs when the immune cells attack a mole for reasons unknown.
- Malignant melanoma.
Signs and Symptoms of Halo nevus
Halo nevi are usually single but may be multiple. This relatively common disorder occurs between the first and fifth decades of life, most frequently during late adolescence. Halo nevi can occur almost anywhere on the body, but most often appear on the trunk, especially the back. The phenomenon seems to follow several stages. The first is a sudden appearance of the white halo around the mole. In the following months or years the central nevus disappears. Finally, the white patch may re-pigment spontaneously and return to normal skin color.
Sign and symptoms may include the following :
- A lighter than normal skin.
- Halo nevi are usually single but may be multiple.
- Rapid eye movements.
- Pigment is absent from the hair, skin ,or iris of eyes that is change in color is observed.
- Functional blindness.
Treatment for Halo nevus
Halo nevi are considered harmless and self-limiting. Hence no treatment is required generally. Halos can be seen as part of a more generalised pigment loss, vitiligo, or in melanoma. Apart from an explanation, no treatment is normally required. However sunscreen should be applied to all the skin during summer to prevent sunburn. The white skin of a halo naevus will burn particularly easily in the sun because it is missing protective melanin pigment. 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.
Treatment may include:
- The skin and eyes must be protected from the sun. Sun glasses may be used.
- In severe cases where the moles are likely to grow strangely or changing colors then surgery may be done.
- 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.