ICD-10 Coding for Dizziness from Allergies
The appropriate ICD-10 code for dizziness caused by allergies is R42 (Dizziness and giddiness), which should be paired with a secondary code specifying the allergic condition (such as J30.1 for allergic rhinitis due to pollen, or other appropriate allergy codes from the J30-J45 range). 1, 2
Primary Code Selection
R42 (Dizziness and giddiness) is the most commonly used ICD-10 code for dizziness presentations, accounting for approximately 80% of dizziness diagnoses in primary care settings and representing the largest category of dizziness-related emergency department visits (27,075 cases over a 3-year period in one large registry study). 1, 2
R42 is a symptom-based code that captures the clinical presentation when dizziness is the primary complaint, regardless of the underlying etiology. 1
Secondary Coding for Allergic Etiology
A secondary diagnosis code from the allergy/hypersensitivity section should be added to specify the allergic trigger, such as:
- J30.1 (Allergic rhinitis due to pollen)
- J30.2 (Other seasonal allergic rhinitis)
- J30.89 (Other allergic rhinitis)
- T78.40 (Allergy, unspecified) if the specific allergen is unknown 3
The ICD-11 classification system has introduced a dedicated section for allergic and hypersensitivity conditions to improve accuracy in capturing these relationships, though ICD-10 remains the current standard in most healthcare systems. 3
Clinical Context Supporting This Coding Approach
Allergies contribute to dizziness symptoms in up to 30% of patients with Ménière's disease, and allergic reactions can result in central symptoms of dizziness including nonspecific chronic imbalance. 4, 5
The mechanism involves allergic activity within the inner ear, with evidence from both cross-sectional and observational studies showing this association. 4
Treatment of underlying allergies through immunotherapy or allergen avoidance has been shown to reduce dizziness symptoms in allergic patients, supporting the causal relationship. 4, 5
Important Coding Considerations
Do not use vestibular-specific codes (H81.x series) unless there is documented vestibular dysfunction beyond the allergic dizziness, as these codes imply specific vestibular pathology like vestibular neuronitis (H81.2) or benign paroxysmal positional vertigo (H81.1). 1, 2
If the patient has documented Ménière's disease with allergic triggers, use H81.0 (Ménière's disease) as the primary code with the allergy code as secondary. 4
Avoid using anaphylaxis codes (T78.2) unless the patient meets clinical criteria for anaphylaxis, which requires acute onset with skin/mucosal involvement plus respiratory compromise or reduced blood pressure. 4