Seborrheic dermatitis (L21)

Browse all the diagnosis codes used for seborrheic dermatitis (l21). For easy navigation, the diagnosis codes are sorted in alphabetical order and grouped by sections. Each section is clearly marked with its description, and the corresponding three-digit code range. This format makes it simple to browse diagnosis codes in this chapter or section and find what you're looking for. We've also added green checkmark icons to label billable codes, and red warning icons for non-billable ones. This makes it easy to identify which codes can be billed.

Clinical Information

Parakeratosis - Persistence of the nuclei of the keratinocytes into the stratum corneum of the skin. This is a normal state only in the epithelium of true mucous membranes in the mouth and vagina. (Dorland, 27th ed)

Parapsoriasis - The term applied to a group of relatively uncommon inflammatory, maculopapular, scaly eruptions of unknown etiology and resistant to conventional treatment. Eruptions are both psoriatic and lichenoid in appearance, but the diseases are distinct from psoriasis, lichen planus, or other recognized dermatoses. Proposed nomenclature divides parapsoriasis into two distinct subgroups, PITYRIASIS LICHENOIDES and parapsoriasis en plaques (small- and large-plaque parapsoriasis).

Pityriasis - A name originally applied to a group of skin diseases characterized by the formation of fine, branny scales, but now used only with a modifier. (Dorland, 27th ed)

Pityriasis Lichenoides - A subgroup of PARAPSORIASIS itself divided into acute and chronic forms. The acute form is characterized by the abrupt onset of a generalized, reddish-brown, maculopapular eruption. Lesions may be vesicular, hemorrhagic, crusted, or necrotic. Histologically the disease is characterized by epidermal necrolysis. The chronic form shows milder skin changes with necrosis.

Pityriasis Rosea - A mild exanthematous inflammation of unknown etiology. It is characterized by the presence of salmon-colored maculopapular lesions. The most striking feature is the arrangement of the lesions such that the long axis is parallel to the lines of cleavage. The eruptions are usually generalized, affecting chiefly the trunk, and the course is often self-limiting.

Pityriasis Rubra Pilaris - A chronic skin disease characterized by small follicular papules, disseminated reddish-brown scaly patches, and often, palmoplantar hyperkeratosis. The papules are about the size of a pin and topped by a horny plug.

Tinea Versicolor - A common chronic, noninflammatory and usually symptomless disorder, characterized by the occurrence of multiple macular patches of all sizes and shapes, and varying in pigmentation from fawn-colored to brown. It is seen most frequently in hot, humid, tropical regions and is mostly caused by MALASSEZIA FURFUR (formerly Pityrosporum orbiculare).

Instructional Notations

Type 2 Excludes

A type 2 excludes note represents "Not included here". An excludes2 note indicates that the condition excluded is not part of the condition represented by the code, but a patient may have both conditions at the same time. When an Excludes2 note appears under a code, it is acceptable to use both the code and the excluded code together, when appropriate.

  • infective dermatitis L30.3
  • seborrheic keratosis L82