How does a subcutaneous tick manifest on a human body? - briefly
A subdermal tick typically presents as a firm, slightly raised nodule at the attachment site, often with a tiny central puncture and minimal pain. Surrounding erythema or mild swelling may develop, and the lesion persists until the parasite is removed.
How does a subcutaneous tick manifest on a human body? - in detail
A subdermal tick becomes lodged beneath the epidermis, often after prolonged attachment in a concealed area such as the scalp, armpit, groin, or interdigital spaces. The initial sign is a small, firm nodule that may be mistaken for a cyst or lipoma. The nodule typically measures 2–5 mm in diameter, feels slightly raised, and may display a central punctum where the mouthparts penetrate the skin.
The surrounding skin can exhibit one or more of the following characteristics:
- Mild erythema or a faint halo of redness surrounding the nodule.
- Slight swelling that may fluctuate with the tick’s feeding cycle.
- Occasional itching or a subtle burning sensation, especially when the tick expands.
As the tick engorges, the nodule enlarges gradually. The surface may remain smooth, but the underlying mass becomes more palpable. In some cases, a translucent, whitish area appears at the center, representing the tick’s engorged body visible through the thin epidermis. The tick’s legs and hypostome are not usually visible externally, but a tiny, dark opening may be observed at the punctum.
Complications can arise if the tick remains embedded for several weeks:
- Localized inflammation leading to a more pronounced erythematous ring.
- Secondary bacterial infection, marked by increased warmth, pus formation, or ulceration.
- Potential transmission of pathogens, which may manifest as systemic symptoms such as fever, malaise, or rash distant from the bite site.
Diagnosis relies on visual inspection and palpation. Dermatoscopic examination often reveals the characteristic “target” pattern: a central dark spot (mouthparts) surrounded by a lighter halo (engorged body). Ultrasonography can confirm the presence of a hypoechoic mass beneath the skin, distinguishing it from other subcutaneous lesions.
Management includes careful extraction with fine‑point forceps, ensuring the mouthparts are removed entirely to avoid retained fragments. Post‑removal care involves cleaning the site with antiseptic, applying a sterile dressing, and monitoring for signs of infection or systemic illness over the following days.