"Redness" - what is it, definition of the term
Erythema is a localized skin discoloration marked by a reddish hue produced by dilation of superficial capillaries; it frequently follows the bite of ectoparasites such as ticks, insects, lice, or fleas, indicating an inflammatory response mediated by histamine and other vasoactive substances.
Detailed information
Erythema caused by ectoparasites manifests as localized swelling of blood vessels in the skin. Ticks embed their mouthparts and inject saliva containing anticoagulants, which triggers an inflammatory response. The resulting discoloration may appear within minutes and persist for several days if the bite is not removed promptly.
Bugs such as bed‑bugs release anesthetic compounds while feeding, allowing them to feed unnoticed. Their saliva contains proteins that provoke a histamine‑mediated reaction, producing a raised, red welt that often clusters in linear patterns corresponding to the insect’s movement.
Lice, whether head or body varieties, bite repeatedly along the scalp or body hair. Each bite induces a small, punctate area of redness that can become papular if scratched. Secondary bacterial infection is a common complication when the skin barrier is breached.
Fleas inject irritants during blood extraction, leading to a prickly, reddened spot that may develop into a larger, inflamed area if multiple bites occur in close proximity. Their saliva also contains enzymes that can exacerbate the vascular response.
Key considerations for managing these reactions:
- Clean the affected area with mild antiseptic solution to reduce bacterial load.
- Apply a cold compress for 10–15 minutes to limit vasodilation.
- Use topical corticosteroid preparations to alleviate inflammation, following dosage instructions.
- Administer oral antihistamines for systemic itching, ensuring no contraindications.
- Inspect surrounding skin for additional bites; remove or treat the parasite source to prevent recurrence.
Persistent or spreading redness, fever, or ulceration warrants medical evaluation, as it may indicate infection or an allergic hypersensitivity. Early intervention limits tissue damage and reduces the risk of complications.