Q: A scabies outbreak was announced at my son’s work, and he was visiting at our home yesterday. What early symptoms should we be watching for and how is it treated?
Scabies is one of the most common skin infestations in the world. It is caused by very tiny parasites called mites. After mating, the female mite burrows just beneath the surface layer of our skin to lay eggs. This causes our body to have an allergic reaction that leads to intense itching and a skin rash.
The infestation is highly contagious when you have prolonged skin-to-skin contact with an infected person, even if they are not yet showing symptoms. Crowded living arrangements such as in nursing homes, frequent skin-to-skin contact as in daycare settings, and close body contact such as bed-sharing or holding hands allow the mites to easily spread. They can live off the human body for up to three days, so it is also possible, just not as likely, to get them from shared towels, clothing and furniture.
The first time you get scabies it can take up to two to six weeks for symptoms to appear because your body needs time to develop the allergic reaction. With future infestations, your symptoms can develop within days due to our immune system’s memory of having the infestation before.
The rash consists of small bumps that look like hives, insect bites, bumps under the skin or pimples that often appear in a line. Sometimes, the rash may have scaly patches that look like eczema. It’s most common in places where our skin folds such as between our fingers and around our nails, along our wrists, elbows, armpits, waist, buttocks, groin and behind our knees. The rash may be more widespread in young children.
The mite’s burrow tracks may appear as small, slightly raised, greyish-white lines and they aren’t always visible on everyone’s skin. Since the rash can appear slightly different from person to person it is easy to misdiagnose scabies as eczema, dermatitis, shingles or insect bites. A scabies infestation is intensely itchy, and the itching gets worse in the evenings and after bathing.
The most common medication to treat scabies is permethrin 5% cream or lotion. Permethrin is an insecticide that works by paralysing the mites which kills them and their eggs. These products are kept behind the counter at the pharmacy and are available from the pharmacist without a prescription.
Start by washing your entire body with a mild liquid cleanser. Once your skin is dry and has completely cooled down, thoroughly rub the product into your skin covering the entire area from your neck to the soles of your feet. Pay close attention to the areas between your fingers and toes, under your fingernails and toenails and all the body fold areas I listed above.
After allowing the product a few minutes to absorb into your skin, change into clean clothes. Wait 12 to 14 hours before washing your body again and then changing into another set of clean clothes. If you wash your hands before the 8-hour mark, reapply the product to that area.
Although the product packaging says a second application seven to 10 days later is only needed if live mites are present or a new rash appears, most healthcare professionals will tell you to do a second treatment anyway to ensure all the mites are killed. Itching may linger for two to four weeks after you have completed the treatment. Your pharmacist can help you select an antihistamine or a corticosteroid cream to help manage the itch.
Since scabies spreads through contact, everyone living in your household and anyone you have shared a bed with should be treated at the same time to reduce the risk of reinfection. Wash all clothing, bedding and towels you used in the previous three days in hot water, and dry them on a hot dryer cycle. Disinfect your home, vacuum carpets and fabric furniture, and seal any non-washable personal items in a plastic bag for a week.
See your doctor if you have scratched open sores into your skin that look infected or if you are still itchy after a month. Sometimes an oral prescription medication called ivermectin is required to treat resistant cases, or if you have a more severe form of scabies called crusted scabies that causes thick crusts to build up on the rash.
Erin Thompson (BSc, BScPharm) is a graduate of Dalhousie University and a community pharmacist practicing at Shoppers Drug Mart in Quispamsis N.B. Her opinions expressed in this column are published for educational and informational purposes only, and are not intended as a diagnosis, treatment or as a substitute for professional medical advice, diagnosis or treatment.