This is a picture of microscopic polyarteritis on the shin. The term polyarteritis means that many blood vessels are inflamed. These nodules are located just below the skin's surface (subcutaneous), are barely felt when pressing on the skin (palpable), and are tender. The skin is typically red (erythematous).
Review Date 1/13/2021
Updated by: Diane M. Horowitz, MD, Rheumatology and Internal Medicine, Northwell Health, Great Neck, NY. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.