आईएसएसएन: 2155-9554
Brent J Doolan, Holly Anderton, Michael Christie, Con Dolianitis
Lichen planus (LP) is a chronic mucocutaneous disease, characterised by an inflammatory immune response with sub-epithelial infiltration of T lymphocytes causing basal epithelial cell damage. Secukinumab is a monoclonal antibody that blocks IL-17A; which is the primary cytokine of Th17 cells involved in the aetiology of inflammatory skin diseases such as psoriasis. Secukinumab has been linked to induction of oral LP, but never directly to cutaneous LP. We report the first case of drug-induced cutaneous LP in the setting of secukinumab for treatment of chronic plaque psoriasis. A 56-year-old man with chronic plaque psoriasis presented with a 2-month history of violaceous and pruritic, thickened plaques on his bilateral lower limbs and buttocks in the setting of secukinumab use for psoriasis. Histological analysis showed a band-like lymphocyte inflammatory infiltrate just beneath the epithelium and was consistent with cutaneous LP. He was treated with topical betamethasone dipropionate cream with moderate effect. Initial laboratory tests including hepatitis and inflammatory screens were within normal limits. We hypothesise that this causal association may be due to a microbial trigger, activating a T-cell mediated immunologic response in CD8+ T-cells and dendritic cells, causing activation of type I interferons and an inflammatory skin response consistent with LP. Clinicians should monitor patients for mucosal and cutaneous LP when using secukinumab or other biologic modulators of IL-17 for extended periods with psoriasis.