Porokeratotic adnexal ostial naevus: review on the entity and therapeutic approach

Porokeratotic adnexal ostial nevus (PAON) is a term that encompass porokeratotic eccrine ostial and dermal duct naevus and porokeratotic eccrine and hair follicle naevus. PAON is a rare adnexal hamartoma characterized by the presence of a cornoid lamella exclusively overlying eccrine acrosyringia or over both, eccrine acrosyringia and hair follicles.

Most of the articles on PAON report its clinical or histopathological characteristics but literature review offer scarce data on the evolution or treatment. We have reviewed it.

We report an 8-year-old boy with presence of bilateral asymtomatic verrucous lesions mostly in left side of the body without other added abnormalities through the twelve-year follow-up. As our case presented cornoid lamella overlying eccrine acrosyringia and hair follicles we diagnosed PEHFN. He received treatment with CO2 ablation in 2004 and in 2012 with marked improvement.

Review of the previous reported cases of PAON show that it is mostly unilateral and that some patients have coexisting problems like seizures, left hemiparesis, scoliosis, deafness, developmental delay, palmoplantar keratoderma, psoriasis, hyperthyroidism, polinerupathy, breast hipoplasia and KID.

PAON responded with tazaroten gel, dithranol short-contact treatment and topical photodynamic therapy but laser treatments appear to be more efficient in most patients.