2025 ICD-10-CM Diagnosis Code L21.8

Approximate Synonyms

The following list of clinical terms are approximate synonyms, alternative descriptions, or common phrases that might be used by patients, healthcare providers, or medical coders to describe the same condition. These synonyms and related diagnosis terms are often used when searching for an ICD-10 code, especially when the exact medical terminology is unclear. Whether you're looking for lay terms, similar diagnosis names, or common language alternatives, this list can help guide you to the correct ICD-10 classification.

Clinical Classification

Clinical Classifications group individual ICD-10-CM diagnosis codes into broader, clinically meaningful categories. These categories help simplify complex data by organizing related conditions under common clinical themes.

They are especially useful for data analysis, reporting, and clinical decision-making. Even when diagnosis codes differ, similar conditions can be grouped together based on their clinical relevance. Each category is assigned a unique CCSR code that represents a specific clinical concept, often tied to a body system or medical specialty.

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 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.

• Hyperparakeratosis

  a morphologic finding indicating increased keratin formation, preservation of the nuclei in the superficial cells, and absence of the stratum granulosum in a skin or squamous mucosa sample.

• Parakeratosis

  abnormal retention of nuclei, and the resulting incomplete keratinization, of epithelial cells in the stratum corneum layer of the skin.

• Tobacco Induced Hyperparakeratosis

  hyperparakeratosis of the oral mucosa caused by chronic tobacco use. it manifests as oral leukoplakia.

• Sebaceous Hyperplasia

  enlargement of the sebaceous glands.

• Senile Sebaceous Hyperplasia

  a hyperplasia of the sebaceous glands. it is usually seen as small yellow papules in the face of middle aged-older population.

• Erythematosquamous Dermatosis

  a skin condition that primarily affects the scalp and face and presents as scaly inflammation. examples include itchy, dry skin and dandruff.

MS-DRG Mapping for ICD-10-CM Code L21.8

Diagnosis-Related Groups (DRGs) are used to classify hospital cases for billing and healthcare management. They help standardize how hospitals and other providers are reimbursed for inpatient care. Patients are grouped based on their principal diagnosis into broader categories called Major Diagnostic Categories (MDCs).

Once assigned to a DRG, the hospital receives a set payment for the patient’s care, regardless of the actual services provided. This fixed rate is intended to cover the typical cost of treating patients within that group. The payment amount depends on the DRG's relative weight, which reflects the expected complexity and cost of care based on the severity of the patient’s condition.

Diagnostic related groups encourage healthcare providers to focus on quality and efficiency in patient care while managing costs effectively. The diagnosis code is present in the following groups for version MS-DRG V42.0 applicable from 10/01/2024 through 09/30/2025.

Convert L21.8 to ICD-9-CM

Below are the ICD-9 codes that most closely match this ICD-10 code, based on the General Equivalence Mappings (GEMs). This ICD-10 to ICD-9 crosswalk tool is helpful for coders who need to reference legacy diagnosis codes for audits, historical claims, or approximate code comparisons.

Patient Education

Dandruff, Cradle Cap, and Other Scalp Conditions

Your scalp is the skin on the top of your head. Unless you have hair loss, hair grows on your scalp. Different skin problems can affect your scalp.

Dandruff is a flaking of the skin. The flakes are yellow or white. Dandruff may make your scalp feel itchy. It usually starts after puberty, and is more common in men. Dandruff is usually a symptom of seborrheic dermatitis, or seborrhea. It is a skin condition that can also cause redness and irritation of the skin.

Most of the time, using a dandruff shampoo can help control your dandruff. If that does not work, contact your health care provider.

There is a type of seborrheic dermatitis that babies can get. It is called cradle cap. It usually lasts a few months, and then goes away on its own. Besides the scalp, it can sometimes affect other parts of the body, such as the eyelids, armpits, groin, and ears. Normally, washing your baby's hair every day with a mild shampoo and gently rubbing their scalp with your fingers or a soft brush can help. For severe cases, your health care provider may give you a prescription shampoo or cream to use.

Other problems that can affect the scalp include:

• Scalp ringworm, a fungal infection that causes itchy, red patches on your head. It can also leave bald spots. It usually affects children.
• Scalp psoriasis, which causes itchy or sore patches of thick, red skin with silvery scales. About half of the people with psoriasis have it on their scalp.

[Learn More in MedlinePlus]

Code History

• FY 2024 - No Change, effective from 10/1/2023 through 9/30/2024
• FY 2023 - No Change, effective from 10/1/2022 through 9/30/2023
• FY 2022 - No Change, effective from 10/1/2021 through 9/30/2022
• FY 2021 - No Change, effective from 10/1/2020 through 9/30/2021
• FY 2020 - No Change, effective from 10/1/2019 through 9/30/2020
• FY 2019 - No Change, effective from 10/1/2018 through 9/30/2019
• FY 2018 - No Change, effective from 10/1/2017 through 9/30/2018
• FY 2017 - No Change, effective from 10/1/2016 through 9/30/2017
• FY 2016 - New Code, effective from 10/1/2015 through 9/30/2016. This was the first year ICD-10-CM was implemented into the HIPAA code set.