What appears after a flea bite? - briefly
A flea bite usually results in a red, itchy welt that can develop into a small papule or a tiny blister.
What appears after a flea bite? - in detail
A flea bite initiates a localized cutaneous response that typically presents as a small, raised, red papule. The lesion often exhibits a central punctum where the insect’s mouthparts penetrated the epidermis. Surrounding erythema may spread a few millimetres from the core, creating a halo‑like pattern.
The evolution of the lesion follows a predictable sequence:
- Immediate pruritus appears within minutes, driven by histamine release.
- Within 12–24 hours, the papule enlarges to 3–5 mm, may become a wheal, and retains intense itching.
- After 48–72 hours, the bump may flatten, turning into a hyper‑pigmented macule that fades over weeks.
Complications can arise, especially in sensitised individuals or when secondary infection occurs:
- Allergic urticaria – widespread hives and swelling beyond the bite site.
- Anaphylaxis – rare, rapid onset of airway compromise and hypotension.
- Bacterial cellulitis – redness, warmth, and pain intensify; purulent discharge may develop.
- Vector‑borne disease – fleas can transmit Bartonella henselae (cat‑scratch disease) or Yersinia pestis (plague), though transmission through a single bite is uncommon.
Management focuses on symptom relief and prevention of infection:
- Topical corticosteroids reduce inflammation and itching.
- Oral antihistamines provide systemic antipruritic effect.
- Antiseptic cleansing of the area limits bacterial colonisation.
- Antibiotic therapy is reserved for confirmed cellulitis or systemic infection.
Monitoring for escalating symptoms, such as expanding erythema, fever, or respiratory distress, warrants prompt medical evaluation.