In simple words: Erythema multiforme is a skin rash.Doctors may use additional codes to describe any related problems or the cause of the rash.

Erythema multiforme is a skin condition characterized by a distinctive rash.Additional codes should be used to specify any adverse effects, such as those caused by drugs (T36-T50 with fifth or sixth character 5), and to identify associated manifestations, including arthropathy (M14.8-), conjunctival edema (H11.42), conjunctivitis (H10.22-), corneal scars and opacities (H17.-), corneal ulcer (H16.0-), edema of eyelid (H02.84-), inflammation of eyelid (H01.8), keratoconjunctivitis sicca (H16.22-), mechanical lagophthalmos (H02.22-), stomatitis (K12.-), and symblepharon (H11.23-).Additional codes may also be used to specify the percentage of skin exfoliation (L49.-).This code excludes staphylococcal scalded skin syndrome (L00) and Ritter's disease (L00).

Example 1: A 30-year-old patient presents with a characteristic target lesion rash consistent with erythema multiforme.The physician documents the diagnosis and orders a complete blood count (CBC) to rule out infection.Code L51 is used for the erythema multiforme.If an associated condition is identified or if the rash is drug-induced, additional codes will be needed., A 25-year-old patient develops a severe case of erythema multiforme with extensive skin involvement after starting a new medication.The physician documents the diagnosis, the drug suspected to have caused the reaction, and orders a skin biopsy. Codes L51 and the appropriate adverse effect code (from T36-T50) are used to accurately represent this scenario., A 45-year-old patient with a history of herpes simplex virus presents with an acute onset of erythema multiforme. The physician notes associated oral ulcers and mild conjunctivitis. Codes L51 and codes for oral ulcers and conjunctivitis are used to represent the case's complete clinical picture.

Complete patient history, including medication history and any recent infections; thorough physical examination, with detailed description of the rash; and results of any relevant laboratory tests (e.g., CBC, skin biopsy).

** Always refer to the latest version of ICD-10-CM coding guidelines for the most accurate and up-to-date information on coding and billing practices.This information is for educational purposes only and should not be considered medical advice.Always consult with a qualified medical professional for any health concerns.