Methotrexate-induced eruptive lentiginosis in resolving psoriasis: a phenomenon possibly dependent on cytokine modulation

Odyssey toward an understanding of acquired postinflammatory lentiginosis

PURPOSE OF REVIEW

Acquired postinflammatory lentiginosis is a phenomenon that has been previously termed 'induction of lentiginosis in assorted dermatoses' or the ILIAD phenomenon.

RECENT FINDINGS

Although some cases have been described as arising exclusively in those who applied topical calcineurin inhibitors (TCIs), other patients have presented with similar findings in other nonatopic disorders (contact dermatitis, psoriasis, lichen planus, focal dermal hypoplasia), and without antecedent use of TCIs.

SUMMARY

Inflammatory skin disorders can produce localized areas of cutaneous lentiginosis, particularly as the inflammation retreats in response to treatment. This post-inflammatory lentiginosis or ILIAD phenomenon may be potentiated by use of topical and systemic anti-inflammatory medications, including TCIs, topical corticosteroids, methotrexate, and systemic biologic agents. Although this phenomenon has not been associated with melanocytic neoplasia, ongoing periodic monitoring for dysplastic changes is reasonable.