In the summer months, we spend more time outdoors with family and friends, especially those from overseas. Insect bites from mosquitoes and sandflies become a pesky issue.
The medical term for rashes caused by insect bites is papular urticaria (PU). PU is thought to be an allergic reaction to mosquito bites. Often, after a few years, the individual becomes desensitised to the insects and the reaction dies down. Hence the old wives’ tale, "Mosquitoes prefer new blood!" This is because the individual has not yet been desensitised to the bites and therefore his immune system reacts more violently. This reaction is especially apparent with tourists visiting our country for the first time.
The insect bites cause intensely itchy rashes which appear as raised bumps and may be in clusters. The rashes are located on the exposed area of the body such as arms, legs and the face.This condition affects children more than adults. One or several members of the family may be affected. The more severe presentation is blister formation which may leave souvenir dark spots that can persist for months and years. The residual hyperpigmentation (dark spots) of this condition is more devastating to the child and parent than the condition itself. It is difficult not to scratch the bumps which may become crusted and infected, forming sores filled with pus (‘fassi foot’) . In severe cases, this is accompanied by regional lymph node enlargement (‘wax and cannon’) and fever.
Sometimes a new bite provokes all the old bumps to become intensely itchy again and it is difficult not to scratch. The itchscratch cycle further worsens the condition and causes sleepless nights for both child and parent.
The bumps can remain for a few days or weeks and may leave dark marks even if the patient did not scratch intensely. This is especially true for people with darker skin colour.
PU may clear up simply by leaving the countryside or seaside where insects are abundant. This is usually the case for children who visit their grandparents for summer. Often this condition may clear up for years to return unexpectedly with repeated exposure. This is especially true for returning residents.
• Avoidance — leave the area where the mosquitoes are abundant until you become desensitised. If unavoidable, wear protective clothing or mosquito repellent on the exposed area.
• Treat infection when present with over-thecounter antibiotics. If fever is present, see a doctor.
• Stop the itch-scratch cycle by taking antihistamines (DPH, Histal) and use a steroid cream (hydrocortisone) on the bumps.
• Use ari Sulfur bar to exfoliate (remove) the dark spots left behind.
Next week — Treating pimples and blemishes (dark spots), is it self-esteem or vanity?
Dr Patricia Yap is a dermatologist at Apex Skin Care and Laser Center.
Contact us at: apexskinclub&gmail.com