Dermatitis due to unspecified substance taken internally

This code signifies an inflammatory reaction of the skin caused by an ingested substance, where the specific agent responsible for the dermatitis is not identified. It represents a generalized skin eruption or localized rash resulting from an internal exposure to an unknown allergen or irritant.

This code is appropriate when a patient presents with dermatitis clearly linked to something they consumed (e.g., food, medication, supplement), but the specific substance causing the reaction cannot be determined from the medical record. Documentation should indicate "dermatitis due to internal substance, unspecified" or similar phrasing.

• Only use this code when the specific internal substance is truly unknown or unspecifiable in the documentation.
• Avoid using this code if the substance is known; instead, use a more specific code from the 692 series (e.g., 692.3 for drugs, 692.5 for food).
• Consider if additional codes are needed to describe the specific type of dermatitis (e.g., urticaria, eczema) if documented.