Sir,

Every year, many people are bitten by a tick, and many are worried about whether they have been infected with the Lyme bacteria or tick-borne encephalitis [1,2]. The most frequent skin change in Lyme disease is erythema migrans. A very rare skin manifestation of Lyme disease is lymphocytoma [2], which is the topic of the present case.

A previously healthy 52-year-old man was referred to a consultant dermatologist because of an encapsulated bluish-violet nodular skin abnormality located at the umbilicus. He was bitten by a tick eight months ago in the same location. He subsequently developed a rash compatible with erythema migrans, which, however, was not treated with antibiotics. Over the past four months, the skin abnormality had come and gone, yet the wound had never healed completely. Treatment with steroid cream had been tried without success. The patient was diagnosed with a lymphocytoma (Fig. 1), and oral antibiotic treatment with doxycycline 100 mg × 2 for fourteen days was initiated. After this, the skin abnormality disappeared.

Figure 1: Lymphocytoma located at the umbilicus.

A lymphocytoma is a very rare skin manifestation of Lyme disease, which appears as an elevated area typically later than erythema migrans and is present for a longer period of time. Histologically, a dense infiltration of lymphocytes is seen in the skin and subcutaneous tissue. In most cases, the skin abnormality will disappear spontaneously [1,2].

Some studies have suggested a possible connection between Borrelia infections and primary cutaneous B-cell lymphoma; however, other studies have not been able to confirm this [3–5].

Lyme disease may cause different skin manifestations. Erythema migrans is the most common and well-known skin manifestation of Lyme disease, while lymphocytoma is a less-known and very rare skin appearance of Lyme disease.

REFERENCES

1. Stanek G, Strle F. Lyme borreliosis-from tick bite to diagnosis and treatment. FEMS Microbiol Rev. 2018;42:233-58.

2. Mahajan VK. Lyme disease:An overview. Indian Dermatol Online J. 2023;14:594-604.

3. Travaglino A, Varricchio S, Pace M, Russo D, Picardi M, Baldo A, et al. Borrelia burgdorferi in primary cutaneous lymphomas:A systematic review and meta-analysis. J Deutsch Dermatol Ges. 2020;18:1379-84.

4. Papadopoulou K, Falk TM, Metze D, Böer-Auer A. No evidence of Borrelia in cutaneous infiltrates of B-cell lymphomas with a highly sensitive, semi-nested real-time polymerase chain reaction targeting the 5S-23S intergenic spacer region. J Eur Acad Dermatol Venereol. 2022;36:836-45.

5. Goteri G, Ranaldi R, Simonetti O, Capretti R, Menzo S, Stramazzotti D, et al. Clinicopathological features of primary cutaneous B-cell lymphomas from an academic regional hospital in central Italy:No evidence of Borrelia burgdorferi association. Leuk Lymphoma. 2007;48:2184-8.