Renbök phenomenon in alopecia areata

Area of Science:

• Dermatology
• Genetics
• Autoimmune Diseases

Background:

• Alopecia areata is an autoimmune condition causing hair loss.
• Perinevoid alopecia is hair loss around a nevus.
• Congenital nevi are moles present at birth.

Observation:

• A second case of alopecia areata sparing a congenital eyebrow nevus is presented.
• This phenomenon is the inverse of perinevoid alopecia.
• It is discussed in relation to the Renbök phenomenon.

Findings:

• The case demonstrates alopecia areata circumscribing a congenital nevus.
• A nevus is considered a genetic mosaic.
• This suggests a genetically determined resistance to alopecia areata within the nevus.

Implications:

• This finding may offer insights into the pathogenesis of alopecia areata.
• Understanding nevus-related alopecia patterns could aid in diagnosis.
• Further research into genetic mosaicism in alopecia areata is warranted.