Familial episodic pain syndrome-3 (FEPS3) is an autosomal dominant disorder characterized by early childhood onset of intense episodic pain mainly affecting the distal lower extremities, but sometimes affecting the upper extremities as well. The pain comes in cycles lasting several days, is exacerbated by fatigue, may be accompanied by sweating, and can be relieved by antiinflammatory medication. Severe episodic pain tends to diminish with age (summary by Zhang et al., 2013). For a discussion of the genetic heterogeneity of familial episodic pain syndrome, see FEPS1 (615040). [from OMIM]