She then presented to our institution with continued fevers, weakness, and a generalized rash. She underwent an extensive autoimmune workup, which revealed the following negative laboratory results: antinuclear antibody (ANA), double-stranded DNA (dsDNA), Scl-70, Smith/ribonuclear protein, SSA, SSB, histone, anticardiolipin antibodies, RF, antineutrophil cytoplasmic antibody, HLA-B27, cryoglobulins, and the myositis panel (Mi-2, Jo-1, PM-Scl, PL-7, PL-12, EJ, OJ, KU, and SRP). The levels of C3, C4, creatine kinase, and antimitochondrial antibody were normal; however, the aldolase level was elevated (18.0 U/L; reference range, 1.2-7.6 U/L) (to convert to microkatals per liter, multiply by 0.0167). Ferritin levels were persistently markedly elevated (16 282 ng/mL; reference range, 9-120 ng/mL) (to convert to picomoles per liter, multiply by 2.247). The results of an infectious workup, including blood and urine cultures and serologic tests for Rocky Mountain spotted fever, Lyme disease, Ehrlichia, and parvovirus B19, were negative. A punch biopsy specimen from a sun-exposed area showed an interface dermatitis with a mixed inflammatory infiltrate.