Painless swelling of external ear - A rare manifestation of Lyme disease

Dr Allison Remiker and colleagues at Ann & Robert H. Lurie Children's Hospital of Chicago, Chicago, USA have reported a case of Lyme disease presenting as swelling of external ear . The case has been published in Journal of Medical case reports.

Lyme disease is the most common tick-borne illness in the USA, Canada, and Europe. Clinical manifestations vary greatly, with localized skin findings functioning as early signs of the disease, followed by disseminated disease. The rarest dermatologic presentation of Lyme is a borrelial lymphocytoma, occurring distinctly in Europe and caused typically by Borrelia afzelii.

A 5-year-old Caucasian European-American boy was referred to Hematology due to concern for a possible autoimmune disorder because of slowly progressing, painless edema and erythema of his right pinna. He was seen recently by Otolaryngology and a primary ear disease was ruled out. Since he had history of immune thrombocytopenia (ITP) at 3 years of age, a concern for an underlying autoimmune disorder was raised. He was in his normal state of health until 4 months prior (in September), when he was noted to have patchy red swelling of his right external ear with no associated pruritus or pain. Initially the erythema waxed and waned; it only lasted hours at a time. However, for the preceding 2 months it had become unremitting. Associated signs included an evanescent circular red rash on his left cheek, also for the last 4 months. He did not experience any constitutional or musculoskeletal symptoms.

On examination, his vital signs were normal for age: temperature 36.9 °C, pulse 124 beats per minute, blood pressure 106/65, weight 11.9 kg, and height 85.2 cm. He appeared well with the examination most notable for an erythematous, edematous right auricle (Fig. 1), which was non-tender to palpation. His left auricle was unaffected and normal in appearance. There were no additional skin findings including rash, bruising, or petechiae. His ear canals were normal with pearl-gray colored tympanic membranes containing no fluid. He was well nourished and in no acute distress. His head was normocephalic. His eyes had normal reactive pupils, no discharge, no erythema or swelling, and no scleral icterus. His nose was normal in appearance. His oropharynx was moist with normal tonsils. His neck was supple with minor bilateral cervical lymphadenopathy. His lungs were clear to auscultation without respiratory distress. A cardiac examination noted a regular rate and rhythm, normal S1 and S2, without murmur. There was no axillary lymphadenopathy. An abdominal examination revealed a soft and non-tender abdomen without organomegaly. There was no inguinal lymphadenopathy. A neurological examination demonstrated an alert child with appropriate responsiveness for age, normal muscle tone, and no weakness. His extremities showed no deformities, joint abnormalities, or edema.

Initially we considered a broad differential diagnosis with this case of painless erythema and swelling of the ear lobule and concha, in the setting of an associated erythematous patch of the cheek. We evaluated for possible mastocytosis with the ear as a location for a hive-like rash. However, the lesion was non-pruritic in nature, and serum tryptase was normal (3.4 mcg/L). We also considered autoimmune and/or rheumatologic conditions. However, a complete blood count with differential (white blood cell 8.9 K/mcL, hemoglobin 11.8 gm/dL, platelet 347 K/mcL, absolute neutrophil count 3.92 K/mcL, absolute lymphocyte count 3.83 K/mcL), lymphocyte subpopulations (CD3 3304 cells/mcL, CD4 1835 cells/mcL, CD8 1300 cells/mcL, CD19 671 cells/mcL, CD16/56,316 cells/mcL, CD4:CD8 1.4), serum immunoglobulins (IgA 144 mg/dL, IgE 72 international units/mL, IgG 1260 mg/dL, IgM 57 mg/dL), and complement C3 109 mg/dL and C4 17.1 mg/dL levels were normal, and anti-nuclear antibodies (ANAs) and an anti-extractable nuclear antigen (ENA) panel (JO-1 antibody, SSB, SSA, anti-Smith, ribonucleoprotein) were negative.

Of interest, his travel history revealed that he had spent 2 months in the Czech Republic over the summer, in a heavily wooded area, and was bit by a significant number of ticks before he returned to the USA just a few weeks prior to the initiation of symptoms.

Collectively, the presence of the auricular lesion, cervical lymphadenopathy, an associated lesion suspicious for erythema migrans (EM), and history of tick exposure led to the possibility of BL. An enzyme-linked immunosorbent assay (ELISA) test for antibodies against B. burgdorferi was positive, although Western blotting for IgM antibodies had 0 of 10 bands and for IgG antibodies 3 of 10 bands, with 5 bands indicating a positive result.

Due to sufficient clinical suspicion, he was placed on amoxicillin 50 mg/kg per day for a 21-day course. Within days of starting the antibiotic, both erythema and edema of the affected area were improved and eventually resolved. The Infectious Disease service was consulted, and on 3-month follow-up his symptoms resolved, and he showed no signs of secondary Lyme disease. A skin biopsy with polymerase chain reaction (PCR) was considered; however, due to clinical improvement this was deemed unnecessary given low yield to identify the organism after successful antibiotic treatment. Nine months following initial diagnosis he remained asymptomatic without return of auricular swelling or new skin, muscle, joint, or neurological findings.

For more details click on the link: https://doi.org/10.1186/s13256-020-02377-x