A 59-Year-Old Woman With Chronic Skin Lesions of the Leg - ANSWER

Diagnosis: Acrodermatitis chronica atrophicans. 

The patient’s photograph of her skin rash taken 3 years ago, which clearly showed that she had erythema chronicum migrans (ECM) at that time, immediately prompted the diagnosis of Lyme disease in the form of acrodermatitis chronica atrophicans (ACA). The histology of the skin biopsy was compatible with this diagnosis, which was confirmed with serology and polymerase chain reaction (PCR). An enzyme-linked immunosorbent assay showed strongly elevated serum antibodies (immunoglobulin G [IgG]) to Borrelia burgdorferi (LiaisonDiaSorin; detection of immunoglobulin against B. burgdorferi, Borrelia afzelii, and Borrelia garinii; IgG >240 UA/mL). Western blotting (Biognost, Borrelia Euroline-WB) detected bands positive against VlsE, p83, p39, p30, and p21 antigens [1]. PCR on the skin biopsy sample (primer sets targeting 23S rDNA; TaqMan) was also positive. The patient was treated for 4 weeks with 100 mg of doxycycline twice a day. Six months later, she had no more lesions. Lyme borreliosis is caused by tick-transmitted spirochetes of the B. burgdorferi sensu lato complex. Although B. burgdorferi sensu stricto is the only species known to cause human disease in North America, at least 5 species can cause the disease in Europe: B. afzelii, B. garinii, B. burgdorferi sensu stricto, Borrelia spielmanii, and Borrelia bavariensis. The clinical symptoms vary widely and depend on the species; some have been described only in Europe [2]. ACA appears to be due only to B. afzelii [3]. This dermatological entity is a rare tertiary manifestation of Lyme disease, manifesting as inflammatory and trophic lesions on acral skin. After an early inflammatory stage with bluish-red discoloration and doughy swelling of the skin, a late atrophic stage appears a few weeks or months later. The skin becomes thin, wrinkled, dry, and transparent because of the loss of epidermal and dermal structures. Vessels may be easily visible, and telangiectasias can be observed. The diagnosis is suggested by dermatologic lesions and a clinical history of tick bites or other well-defined manifestations of Lyme borreliosis, such as ECM, shown in our patient’s picture. Confirmation of the diagnosis is obtained by serological testing (enzyme immunoassay and Western blotting). These methods might increase diagnostic accuracy over that of PCR, which has a sensitivity of about 50%, depending on primer set [4]. Treatment of ACA is usually based on a course of antibiotic treatment with ceftriaxone [5] or doxycycline [6] for 21–28 days. Complete disappearance of lesions is normally described [7, 8]. The absence of treatment can lead to fibrotic nodules and/or patchy or bandlike indurations that may limit joint movement without treatment.

Clinical Infectious Diseases 2013;57(12):1782

DOI: 10.1093/cid/cit667