Allergic purpura

This code represents Henoch-Schönlein purpura (HSP), a systemic vasculitis characterized by palpable purpura, arthralgia, abdominal pain, and renal involvement. It is an immune-mediated condition, often following an upper respiratory infection, where IgA deposits in small blood vessels lead to inflammation and leakage.

Use this code for patients diagnosed with Henoch-Schönlein purpura based on characteristic clinical findings. Documentation should clearly describe the presence of purpuric rash, often accompanied by joint pain, gastrointestinal symptoms, or evidence of kidney involvement.

• Differentiate from other causes of purpura; this code is specific to allergic (Henoch-Schönlein) purpura.
• Code any associated manifestations, such as nephritis (e.g., 583.x), arthritis (e.g., 716.x), or gastrointestinal hemorrhage (e.g., 578.x), as secondary diagnoses.
• Ensure the physician's documentation explicitly states "allergic purpura" or "Henoch-Schönlein purpura" to support this specific diagnosis.