Cutaneous mastocytosis

This code describes a form of mastocytosis primarily affecting the skin, characterized by an abnormal accumulation of mast cells within the dermis. It typically presents as lesions such as macules, papules, or nodules, which may be pruritic and urticate upon rubbing (Darier's sign).

Assign this code for acquired cutaneous mastocytosis in adult or pediatric patients where the disease is confined to the skin. Documentation should clearly specify "cutaneous mastocytosis" and rule out systemic involvement or congenital forms. This code is appropriate when the mast cell proliferation is localized to the skin without evidence of extracutaneous disease.

• Do not use this code for congenital forms of cutaneous mastocytosis; refer to Q82.2.
• Distinguish carefully between purely cutaneous and systemic mastocytosis; systemic forms require different coding.
• Ensure documentation specifies the cutaneous nature to avoid confusion with extracutaneous mastocytoma.