Triangular alopecia

A type of non-scarring hair loss

Triangular alopecia, also known as temporal triangular alopecia or congenital triangular alopecia, is a condition characterized by a localized area of hair loss, typically occurring in the temporal region of the scalp. This condition is non-scarring, meaning that the hair follicles are not permanently damaged, and it is usually present from birth or early childhood.

Presentation

File:Triangular Alopecia.jpg

Triangular alopecia in a child

Triangular alopecia typically presents as a well-defined, triangular or oval patch of hair loss on the scalp, most commonly located in the frontotemporal region. The affected area is usually devoid of hair, although some fine vellus hairs may be present. The skin in the area appears normal, without signs of inflammation or scarring.

The condition is often noticed in early childhood, but it can sometimes be identified later in life. It affects both males and females equally and is usually unilateral, although bilateral cases have been reported.

Causes

The exact cause of triangular alopecia is not well understood. It is believed to be a developmental anomaly rather than a genetic disorder, although some familial cases have been documented. The condition is not associated with any systemic diseases or other abnormalities.

Diagnosis

The diagnosis of triangular alopecia is primarily clinical, based on the characteristic appearance of the hair loss. A dermatologist may use a dermatoscope to examine the area more closely. In some cases, a skin biopsy may be performed to rule out other causes of hair loss, such as alopecia areata or tinea capitis.

Treatment

Treatment for triangular alopecia is not always necessary, as the condition is benign and does not progress. However, for cosmetic reasons, some individuals may seek treatment options. These can include:

• Topical minoxidil: This medication can sometimes stimulate hair growth in the affected area.
• Surgical options: Hair transplantation can be considered for those seeking a permanent solution.

Prognosis

The prognosis for individuals with triangular alopecia is excellent, as the condition is non-progressive and does not affect overall health. The main concern is cosmetic, and treatment is optional based on personal preference.

Related pages

• Alopecia areata
• Hair loss
• Dermatology

Genetic Considerations

Autosomal dominant inheritance pattern

While triangular alopecia is not typically considered a genetic disorder, there have been reports of familial cases suggesting a possible genetic component. In such cases, an autosomal dominant pattern of inheritance has been proposed, although this is not definitively established.

See also

• List of cutaneous conditions
• Scalp conditions