M31.0
BillableHypersensitivity angiitis
HCC Category Mapping
V28HCC 93 — Rheumatoid Arthritis and Inflammatory Connective Tissue Disease
0.175V24HCC 40 — Rheumatoid Arthritis and Inflammatory Connective Tissue Disease
0.307ESRDHCC 40 — Rheumatoid Arthritis and Inflammatory Connective Tissue Disease
0.000RxHCCHCC 84 — Vasculitis and Other Autoimmune Disorders
0.000What This Code Means
An allergic reaction affecting blood vessels that causes inflammation and tissue damage, typically triggered by medications or infections.
Coding Tips
- •Document the triggering agent (drug, infection, or other cause) when possible
- •Distinguish from other vasculitides by the hypersensitivity mechanism
Clinical Significance
Hypersensitivity angiitis represents a drug-induced or infection-triggered small vessel vasculitis that typically affects skin and may involve other organs. While often less severe than systemic vasculitis, it requires identification and removal of triggering agents and monitoring for systemic involvement.
Documentation Requirements
- ✓Clinical evidence of small vessel vasculitis
- ✓Documentation of suspected triggering agent (drug, infection)
- ✓Skin biopsy showing leukocytoclastic vasculitis
- ✓Timeline relating exposure to symptom onset
- ✓Assessment of organ involvement beyond skin
- ✓Response to trigger removal or treatment
- ✓Monitoring for recurrence
- ✓Exclusion of systemic vasculitis syndromes
Commonly Confused Codes
L95.9 — Vasculitis limited to skin, unspecified (when only skin involvement)M30.0 — Polyarteritis nodosa (medium vessel involvement)M31.7 — Microscopic polyangiitis (systemic small vessel vasculitis)T88.6 — Anaphylactic reaction due to adverse effect of correct drug (acute allergic reaction)L27.0 — Generalized skin eruption due to drugs and medicaments