Macular lymphocytic arteritis
In a review of 32 cases of MLA, the mean age of onset was 40 years, with onset ranging from 6-73 years. Women and children represented 84% and 6% of all cases that were reviewed, respectively. Individuals of African descent represented the largest ethnic group affected by MLA.
The etiology of MLA is unknown. Overlap of some histological features between MLA and certain stages of cutaneous polyarteritis nodosa (C-PAN) have raised the question of whether MLA actually exists as part of a spectrum with C-PAN.
L95.8 – Other vasculitis limited to the skin
46286007 – Lymphocytic vasculitis of skin
Differential Diagnosis & Pitfalls
- Pigmented purpuric dermatoses
- Postinflammatory hyperpigmentation
- Lichen planus pigmentosus – Most commonly affects sun-exposed areas including the face and neck.
- Ashy dermatosis – Typically presents as gray-blue macules and patches affecting the trunk and proximal extremities.
- Drug-induced pigmentation
- Sneddon syndrome
- Cutaneous or systemic polyarteritis nodosa – Typical presentation includes tender subcutaneous nodules with possible ulceration.
- Granulomatosis with polyangiitis
- Connective tissue diseases (systemic lupus erythematosus, rheumatoid arthritis, dermatomyositis)
- Hematologic or hypercoagulable conditions (antiphospholipid antibody syndrome, cryoglobulinemia, essential thrombocythemia, polycythemia vera, protein C or S deficiency, disseminated intravascular coagulopathy)