What does a tick bite site infected with Borrelia look like? - briefly
The lesion commonly presents as a red, expanding erythema with a central area of pallor, forming a characteristic «bull’s‑eye» pattern that appears 3‑30 days after the bite. Mild itching or warmth may accompany the rash, while ulceration is unusual.
What does a tick bite site infected with Borrelia look like? - in detail
The skin lesion that develops after a tick bite transmitting Borrelia species typically presents as a rapidly expanding erythematous macule or papule. Initial redness may be faint, measuring a few millimetres, and enlarges over days to weeks, often reaching diameters of 5 cm or more. The most characteristic pattern is a concentric ring with a paler centre, creating a “bull’s‑eye” appearance; however, uniform solid redness without central clearing also occurs.
Key visual features include:
- Shape: generally circular, occasionally irregular when coalescing with adjacent lesions.
- Border: well‑defined, slightly raised, sometimes exhibiting a faint ridge.
- Colour: bright red to pink; central area may appear lighter or exhibit slight blanching.
- Texture: smooth surface; occasional mild scaling or papular components at the periphery.
- Progression: lesion expands outward while the centre may fade, maintaining overall size increase.
Multiple lesions can appear if spirochetes disseminate, presenting as several similar rings on distant body sites. In some cases, vesicular or ulcerative changes develop, especially in immunocompromised individuals. Accompanying systemic signs—fever, headache, arthralgia—may emerge but are not visual components of the cutaneous manifestation.
Recognition of these patterns enables early diagnosis and prompt antimicrobial therapy, reducing risk of further organ involvement.