The hyper IgE syndromes (HIES) are rare primary immune deficiencies characterized by elevated serum IgE, rash, and recurrent bacterial infections of the skin and lung. Autosomal dominant HIES, the most common disease in this group, results from STAT3 mutations and has a variety of connective tissue and skeletal abnormalities. The genetic etiologies of the more rare autosomal recessive forms still need delineation. Treatment of these syndromes has relied on prophylactic and therapeutic antimicrobial agents and aggressive skin care. The new and evolving genetic and immunologic understandings of this previously elusive set of diseases should lead to more effective disease-specific therapies.