Is TNF-α Inhibitor-Induced Psoriasiform Dermatitis Always Psoriasiform?

Tumor necrosis factor-α inhibitors (TNFIs) have significantly improved the quality of life for patients with psoriasis and psoriatic arthritis. Despite their beneficial effects, TNFIs have been reported to cause paradoxical ‘psoriasiform’ eruptions.1 Although this nomenclature has become pervasive in the dermatology lexicon, there is a growing body of literature highlighting the protean clinical presentation of this eruption (Figure 1), which could ultimately lead to a delayed diagnosis.2-5 The diversity of the morphology highlights the importance of identifying key histopathologic characteristics, which to date have not been well-characterized.2