Psoriasis exhibits a broader histopathologic spectrum, according to a recent study. To that end, the presence of some non-classic features does not necessarily exclude the possibility of psoriasis. Minimal clinical diagnostic criteria were informally validated and applied to a consecutive series of biopsies histologically consistent with psoriasis. Clinical confirmation required 2 of the following criteria: 1. classic morphology, 2. classic distribution, 3. nail pitting, 4. family history, with #1 and/or #2 as 1 criterion in every case. 51 biopsies from 46 patients were examined. Researchers found:
- Classic features of psoriasis included hypogranulosis (96%), club-shaped rete ridges (96%), dermal papilla capillary ectasia (90%), Munro microabscess (78%), suprapapillary plate thinning (63%), spongiform pustules (53%), and regular acanthosis (14%).
- Non-classic features included irregular acanthosis (84%), junctional vacuolar alteration (76%), spongiosis (76%), dermal neutrophils (69%), necrotic keratinocytes (67%), hypergranulosis (65%), neutrophilic spongiosis (61%), dermal eosinophils (49%), compact orthokeratosis (37%), papillary dermal fibrosis (35%), lichenoid infiltrate (25%), plasma cells (16%), and eosinophilic spongiosis (8%).
Chau T, Parsi KK, Orgawa T, et al. Psoriasis or not? Review of 51 clinically confirmed cases reveals an expanded histopathologic spectrum of psoriasis. [Published online ahead of print August 22, 2017]. J Cutan Pathol. doi:10.1111/cup.13033.