In most instances, scabies is not a big deal and can be treated with a little help. Human scabies is caused by an infestation of the skin by the human itch mite (Sarcoptes scabiei var. hominis). The microscopic scabies mite burrows into the upper layer of the skin where it lives and lays its eggs. Ready for some images?
Image credit from DermNetNZ.org
Image credit from DermNetNZ.org
This is what the scabies mite looks like. Image credit from DermNetNZ.org
Symptoms of Scabies
Scabies signs and symptoms include:
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Itching, often severe and usually worse at night
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The skin rash may appear pimple-rash
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Thin, irregular burrow tracks made up of tiny blisters or bumps on your skin (which is the eggs of the adult female mite)
The burrows or tracks typically appear in folds of skin. Though almost any part of the body may be involved, in adults and older children scabies is most often found:
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Between the fingers
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In the armpits
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Around the waist
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Along the insides of the wrists
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On the inner elbows
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On the soles of the feet
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Around the breasts
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Around the male genital area
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On the buttocks
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On the knees
In infants and young children, common sites of infestation usually include the:
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Scalp
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Palms of the hands
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Soles of the feet
If you've had scabies before, signs and symptoms may develop within a few days of exposure to the mites. If you've never had scabies, it can take 4-8 weeks for signs and symptoms to begin.
Scabies can also be confused for other non-infectious skin conditions, such as eczema and psoriasis. If you have any doubts whether you are having scabies or not, consult a GP or skin specialist.
Spreading of scabies
It is usually the impregnated female scabies mite that is spread by direct, prolonged, skin-to-skin contact with a person who has scabies. Scabies occurs worldwide and affects people of all races and social classes. Scabies can spread rapidly under crowded conditions where close body contact is frequent. Institutions such as nursing homes, extended-care facilities, and prisons are often sites of scabies outbreaks. You can still spread scabies to other people even if you don't have any signs or symptoms yet.
How to treat scabies?
The household members and sexual contacts (within a month) of the infested person are recommended to undertake treatment for scabies as well. This is because these parties may have prolonged skin-to-skin contact with people infected by scabies. All persons should be treated at the same time to prevent reinfestation. Scabies may sometimes be sexually-acquired in adults, but is rarely sexually-acquired in children.
The medications used to treat scabies can be easily purchased at any pharmacy. Such products are known as the scabicides, in which they kill scabies mites and some even kill mite eggs. Scabicides are available in lotion or cream. Here are some common scabicides in Malaysia:
All images credit to https://www.alpropharmacy.com/
In general, scabicide lotion or cream should be applied to all areas of the body from the neck down to the feet and toes. It is left for overnight (8 to 10 hours), then followed by washing the lotion away. Nevertheless, you should always follow the instructions on the product or consult your pharmacist on the correct method of using these products.
In addition, when treating infants and young children, scabicide lotion or cream also should be applied to their entire head and neck because scabies can affect their face, scalp, and neck, as well as the rest of their body. Only permethrin or sulfur ointment may be used in infants.
Because the symptoms of scabies are due to an allergic reaction to mites and their feces (scybala), itching still may continue for several weeks after treatment even if all the mites and eggs are killed. If itching still is present more than 2 to 4 weeks after treatment or if new burrows or pimple-like rash lesions continue to appear, retreatment may be necessary.
If there is any skin sores or breaking of skin observed, you should see a doctor for an appropriate antibiotic treatment.
What else should you do?
Scabies is prevented by avoiding direct skin-to-skin contact with an infested person or with items such as clothing or bedding used by an infested person. Bedding, clothing, and towels used by infected persons or their household, sexual, and close contacts anytime during the three days before treatment should be washed in hot water and drying in a hot dryer, by dry-cleaning, or by sealing in a plastic bag for at least 72 hours. This is because scabies mites generally do not survive more than 2 to 3 days away from human skin. Children and adults usually can return to child care, school, or work the day after treatment.
Can I get scabies from my pets?
No. Animals do not spread human scabies. Pets can become infected with a different kind of scabies mite that does not survive or reproduce on humans but causes “mange” in animals. If an animal with “mange” has close contact with a person, the animal mite can get under the person’s skin and cause temporary itching and skin irritation. However, the animal mite cannot reproduce on a person and will die on its own in a couple of days. Although the person does not need to be treated, the animal should be treated because its mites can continue to burrow into the person’s skin and cause symptoms until the animal has been treated successfully.
Will insecticide help?
Use of insecticide sprays and fumigants is not recommended.
Crusted (Norwegian) scabies
Crusted scabies, or Norwegian scabies as it was formally known, is a highly contagious hyper infestation with Sarcoptes scabiei var hominis. To put into perspective,individuals with crusted scabies are estimated to have up to 4,000 mites per gram of skin. Patients are often infected with over 1 million mites. Compare this to the majority of patients with scabies, who are infected with around 10–20 mites.
Image credit from DermNetNZ.org
Image credit from DermNetNZ.org
Although the exact reasons behind crusted scabies is unknown, it is more commonly seen in immunocompromised patients. Crusted scabie can also be misdiagnosed by doctors as psoriasis or seborrheic dermatitis. Persons with crusted scabies and their close contacts, including household members, should be treated rapidly and aggressively to avoid outbreaks. Institutional outbreaks can be difficult to control and require a rapid, aggressive, and sustained response. Rooms used by a patient with crusted scabies should be thoroughly cleaned and vacuumed after use.
References:
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Mayo Clinic - Scabies https://www.mayoclinic.org/diseases-conditions/scabies/symptoms-causes/syc-20377378
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CDC- Scabies https://www.cdc.gov/parasites/scabies/gen_info/index.html
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DermNet NZ - Crusted scabies https://dermnetnz.org/topics/crusted-scabies/
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Cover image credit: DermNetNZ.org
