2026 ICD-10-CM Diagnosis Code L43.2Lichenoid drug reaction
ICD-10-CM Codes›L00–L99›L40-L45›L43
- Billable — Valid for Submission
- Not Chronic
L43.2 is a billable ICD-10-CM diagnosis code for lichenoid drug reaction. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 606 through 607. Coders also document this condition as drug-induced oral lichenoid reaction. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Drug induced or toxic related condition and Other specified inflammatory condition of skin.
Code Identity
Code Classification
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Drug-induced oral lichenoid reaction
- Lichenoid allergic contact reaction
- Lichenoid allergic contact reaction caused by amalgam
- Lichenoid drug eruption
- Oral lichenoid reaction
Tabular List NotesGuidance
Coding notes and annotation back-references applicable to this code.
Use Additional Code
The “use additional code” indicates that a secondary code could be used to further specify the patient’s condition. This note is not mandatory and is only used if enough information is available to assign an additional code.
Index to Diseases and InjuriesGuidance
External Cause of Injuries IndexGuidance
References for this code in the External Cause of Injuries Index.
- Reaction
- drug NEC
- lichenoid
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Clinical InformationClinical
Lichen Planus
an inflammatory, pruritic disease of the skin and mucous membranes, which can be either generalized or localized. it is characterized by distinctive purplish, flat-topped papules having a predilection for the trunk and flexor surfaces. the lesions may be discrete or coalesce to form plaques. histologically, there is a saw-tooth pattern of epidermal hyperplasia and vacuolar alteration of the basal layer of the epidermis along with an intense upper dermal inflammatory infiltrate composed predominantly of t-cells. etiology is unknown.Lichen Planus, Oral
oral lesions accompanying cutaneous lichen planus or often occurring alone. the buccal mucosa, lips, gingivae, floor of the mouth, and palate are usually affected (in a descending order of frequency). typically, oral lesions consist of radiating white or gray, velvety, threadlike lines, arranged in a reticular pattern, at the intersection of which there may be minute, white, elevated dots or streaks (wickham's striae). (jablonski, illustrated dictionary of dentistry)Atrophic Lichen Planus
a rare form of lichen planus that is characterized by well-demarcated, white-bluish papules or plaques with central atrophy.Bullous Lichen Planus
a rare form of lichen planus that is characterized by the formation of vesico-bullous lesions on top of preexisting lichen planus papules or on normal skin.Hypertrophic Lichen Planus
a form of lichen planus that is characterized by plaques of markedly thickened skin that is often extremely pruritic and localized to the lower legs. it can result in permanent pigmentation and scarring.Lichen Planus
a chronic, recurrent, pruritic inflammatory disorder of unknown etiology that affects the skin and mucus membranes. it presents with rashes and papules that tend to resolve spontaneously. it may be associated with hepatitis c. certain drugs that contain arsenic or bismuth are associated with reactions mimicking lichen planus.Lichen Planus-Like Keratosis|Lichenoid Keratosis
a benign intraepidermal squamoproliferative neoplasm characterized by irregular acanthosis, hyperkeratosis, parakeratosis, and prominent chronic inflammation.Lichenoid Drug Eruption|Drug-induced Lichen Planus|Drug-induced Lichen Planus
a red or violaceous flat-topped, papular eruption that is induced by exposure to a variety of medications or environmental agents.Oral Lichen Planus
a chronic, autoimmune inflammatory condition of the mucous membranes in the oral cavity that affects approximately two percent of the population and is most often seen in middle aged women. it is characterized by white, lacy patches; red, swollen tissue; papules and plaques; or open sores. the lesions are typically bilateral.
Patient EducationClinical
Drug Reactions
Most of the time, medicines make our lives better. They reduce aches and pains, fight infections, and control problems such as high blood pressure or diabetes. But medicines can also cause unwanted reactions, such as drug interactions, side effects, and allergies.
The full article covers:
- What is a drug interaction?
- What are side effects?
- What are drug allergies?
- How can I stay safe when taking medicines?
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert L43.2 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About L43.2Overview
Is L43.2 (Lichen planus) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report lichenoid drug reaction on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What MS-DRG does L43.2 group to?
When lichenoid drug reaction is the principal diagnosis on an inpatient stay, it groups to MS-DRG 606, 607, with relative weights from 0.9064 to 1.5132 depending on complications. Higher weights mean higher Medicare reimbursement.
What is the ICD-9 equivalent of L43.2?
Under the General Equivalence Mappings, lichenoid drug reaction converts to ICD-9-CM 697.0 (lichen planus). The mapping is approximate, so confirm the match fits the documentation.
Footnotes
[1] Not chronic - A diagnosis code that does not fit the criteria for chronic condition (duration, ongoing medical treatment, and limitations) is considered not chronic. Some codes designated as not chronic are acute conditions. Other diagnosis codes that indicate a possible chronic condition, but for which the duration of the illness is not specified in the code description (i.e., we do not know the condition has lasted 12 months or longer) also are considered not chronic.
