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  2. ICD-10-CM Codes List
  3. L00–L99
  4. L40-L45
  5. Psoriasis (L40)

Psoriasis (L40)

ICD-10 code L40 categorizes various forms of psoriasis, a chronic inflammatory skin condition characterized by red, scaly patches. These codes help differentiate among specific types such as plaque psoriasis (L40.0), pustular forms (L40.1–L40.4), and psoriatic arthritis (L40.5 series), enabling accurate diagnosis and treatment planning.

The ICD-10 code for psoriasis includes numerous subcodes that clarify the particular type or manifestation. For example, L40.0 covers psoriasis vulgaris, often called plaque psoriasis or chronic stable plaque psoriasis, which presents as thick, silvery plaques. L40.1 identifies generalized pustular psoriasis, sometimes referred to as acute pustular skin eruption, involving widespread pustules. Localized pustular variants like L40.2 (acrodermatitis continua) and L40.3 (pustulosis palmaris et plantaris) involve the hands and feet. Less common forms such as L40.4 (guttate psoriasis) often present with small drop-like lesions. Psoriatic arthritis is specified with codes L40.50 to L40.59, describing joint involvement types including distal interphalangeal arthropathy and juvenile onset. The L40.8 and L40.9 codes cover other or unspecified psoriasis, useful when clinical details are limited or for rare variants. Using these ICD-10 codes for psoriasis ensures precise classification between skin-only and arthropathic forms and aids healthcare providers and coders in selecting the appropriate diagnosis in medical records.

Clinical Terms

The following clinical terms provide additional context, helping users better understand the clinical background and common associations for each diagnosis listed in this section. Including related terms alongside ICD-10-CM codes supports coders, billers, and healthcare professionals in improving accuracy, enhancing documentation, and facilitating research or patient education.

Arthritis, Psoriatic

A type of inflammatory arthritis associated with PSORIASIS, often involving the axial joints and the peripheral terminal interphalangeal joints. It is characterized by the presence of HLA-B27-associated SPONDYLARTHROPATHY, and the absence of rheumatoid factor.

Guttate Psoriasis

A skin condition, typically emerges suddenly and frequently occurs after an infection such as STREPTOCOCCAL INFECTION. While prevalent among children, it can also manifest in young adults. Its defining feature is the eruption of small, red, scaly patches that typically appear on the arms, legs, and torso.

Psoriasis

A common genetically determined, chronic, inflammatory skin disease characterized by rounded erythematous, dry, scaling patches. The lesions have a predilection for nails, scalp, genitalia, extensor surfaces, and the lumbosacral region. Accelerated epidermopoiesis is considered to be the fundamental pathologic feature in psoriasis.

Streptococcal Infections

Infections with bacteria of the genus STREPTOCOCCUS.