Ticks and Tick Bites Presenting as "Funny Moles": A Review of Different Presentations and a Focus on Tick-borne Diseases.

Purpose: To describe a man with an adherent tick mimicking a melanoma, summarize the salient features of this condition, and review other cases of ticks mistaken for dermatoses. Background: Ticks are obligatory ectoparasites. Disease-causing ticks belong to two families: Ixodidae (hard ticks) and Argasidae (soft ticks). Ticks thrive by consuming blood from animal hosts, and the transfer of infected blood from one host to the next is the method by which ticks spread disease. Materials and methods: The authors describe a man who presented to their dermatology clinic in New York with an unusual black pigmented lesion on the right zygomatic region of his face. He was worried about how rapidly the lesion had developed and the tingling of the skin surrounding it. Since the patient had a history of nonmelanoma skin cancer, he was concerned that the lesion was a melanoma. An excisional biopsy of the lesion revealed a non-Ixodes tick with a surrounding tick-bite reaction.
Results: Ticks cause cutaneous manifestations through physical trauma and their salivary contents. A number of reports describe a similar phenomenon of a persistent tick being mistaken for a nodule or tumor. Management includes complete removal of a tick, either mechanically or surgically, along with the appropriate work-up for tick-borne diseases in the relevant geographic location. The decision to test for systemic disease depends on the clinical presentation of the patient and geographic location of the tick bite.
Conclusion: A patient presented to the authors' dermatology clinic with a pigmented lesion suspicious for a melanoma, but the lesion was actually an adherent non-Ixodes tick. This case illustrates the importance of keeping insects and arthropods in the differential diagnosis of a sudden- and recent-onset pigmented skin lesion.