Psoriasis ICD-10-CM codes

Plaque psoriasis, the common form, is L40.0 (psoriasis vulgaris). Use L40.9 only when the record says psoriasis with no type. Other 4th characters identify guttate psoriasis (L40.4), generalized pustular psoriasis (L40.1), palmoplantar pustulosis (L40.3), acrodermatitis continua (L40.2), and other psoriasis such as inverse or scalp psoriasis (L40.8).

Psoriatic arthritis is a combination code in L40.5-, which sits in chapter 12 even though it is a joint disease. L40.50 is the unspecified form; L40.51 is distal interphalangeal psoriatic arthropathy, L40.52 arthritis mutilans, L40.53 psoriatic spondylitis, L40.54 juvenile psoriatic arthropathy, and L40.59 other. An L40.5- code covers both the skin and joint disease, so do not add a separate M-chapter arthritis code for the same condition.

Parapsoriasis is a different diagnosis and is coded to L41 (L41.9 unspecified). Patients on biologics or JAK inhibitors for psoriasis should carry Z79.620 or Z79.622 for long-term immunosuppressive therapy, and Z79.52 when on chronic systemic steroids.