How does a subcutaneous tick cause the appearance of pimples? - briefly
A buried tick injects saliva containing anticoagulants and irritants, provoking a focal inflammatory reaction that forms a red, raised papule often mistaken for a pimple. The lesion may contain a central punctum where the tick’s mouthparts remain attached, distinguishing it from typical acne.
How does a subcutaneous tick cause the appearance of pimples? - in detail
A tick that penetrates the dermis deposits saliva containing anticoagulants, proteolytic enzymes, and antigens. These compounds disrupt normal hemostasis, degrade extracellular matrix, and provoke an immediate immune response.
The host reacts by releasing histamine and pro‑inflammatory cytokines (IL‑1, IL‑6, TNF‑α). Vasodilation and increased vascular permeability cause edema, producing a raised, red papule at the bite site.
Neutrophils and macrophages migrate to the area to phagocytose foreign material. Their activity generates additional tissue swelling and may create a central point of necrosis. When the necrotic core becomes colonized by skin flora—most commonly Staphylococcus aureus or Streptococcus pyogenes—a pustular lesion forms, resembling a pimple.
Typical progression:
- Immediate erythema and swelling (minutes to hours).
- Development of a firm papule (1–2 days).
- Onset of a pustule or tiny abscess if bacterial infection occurs (3–5 days).
- Possible central ulceration or crusting as the lesion resolves (1–2 weeks).
Persistent lesions may indicate a retained mouthpart or ongoing infection, requiring medical extraction and antimicrobial therapy. Early removal of the tick reduces the amount of saliva introduced, limiting the inflammatory cascade and preventing pustule formation.