Scabies is a highly contagious parasitic skin infection caused by the mite Sarcoptes scabiei. The mite lives on the skin and can survive for 24 to 36 hours at room temperature and average humidity, and remain capable of infestation and epidermal burrowing.
Scabies is very contagious and occurs in both sexes, at all ages, in all ethnic groups, and at all socioeconomic levels. According to Giuseppe et al (2016) approximately 300 million of scabies are recorded cases every year worldwide.
The risk of severe outbreaks and complicated scabies is common in congested areas such as, institutions (including nursing homes and hospitals) , among socially disadvantaged populations and immune compromised hosts.
Causes and transmission of scabies
Infestation by the mite Sarcoptes scabiei.
Close skin-to-skin contact with an infected person ( especially sexual intercourse or an infected family member).
Through the sharing of clothes, bedding or other fomites with an infected person.
Symptoms of scabies
When first infected, it usually takes two to six weeks before symptoms occur, but if a person develops a second infection later in life, symptoms may begin within a day. An individual can be infectious and can spread scabies before they even know they are have the disease. The following symptom may be detected:
The main symptom of scabies is Itching, often due to a reaction (allergy) to the mites (or their saliva, poo (faeces) or eggs). It is often severe and may spread to other areas of the body. The itch is generally worse at night and after a hot bath.
Mite tunnels (burrows) may be seen on the skin in form of fine, dark, or silvery lines about 2-10 mm long. These may be seen on the loose skin between the fingers (the web spaces), the inner surface of the wrists, and the hands. It can also occur on any part of the skin. The burrows may not be noticed until a rash or itch develops.
Rash usually appears after the itch. It can appear anywhere on the body and is typically a blotchy, lumpy red rash that. The rash is often most obvious on the inside of the thighs, parts of the tummy (abdomen) and buttocks, armpits, and around the nipples in women. Some people may develop unusual rashes which may be confused with other skin conditions.
Scratching due to intense itching may occur. It can cause minor skin damage; damaged skin may become infected by other germs (bacteria).
Aggravation or worsening of pre-existing skin conditions, particularly itchy skin problems such as eczema, or problems such as psoriasis may occur.
Diagnosis of scabies may include:
A definitive diagnosis is made by finding either the scabies mites or their eggs and fecal pellets, either scraping a suspected area, mounting the sample in potassium hydroxide and examining it under a microscope, or using dermoscopy to examine the skin directly.
Recognizing the typical appearance of the scabies rash by a doctor.
Clinically in geographical areas where it is common when diffuse itching presents along with either lesions in two typical spots or there is itchiness of multiple members of a household.
The burrows made by the mites within the skin is detected, the suspected area is rubbed with ink from a fountain pen or a topicaltetracycline solution, which glows under a special light. The skin is then wiped with an alcohol pad. The skin of an infected person will show the characteristic zigzag or S pattern of the burrow.
Prevention of scabies
If an item belonging to a victim cannot be washed this way, it can be stored away from human contact for at least three days to eliminate mites
Avoid close skin-to-skin contact with an infected person until they have been treated.
Hospital staff should use recommended gloves and gowns when treating patients who have a suspicious rash and itching.
Simultaneous treatment of all close asymptomatic contacts to reduce rates of recurrence.
Clothing, towels, and bedding from an affected person should be regularly washed in hot water and dried in a dryer.
Cut your nails, and clean under them thoroughly to remove any mites or eggs that may be present.
Vacuum carpets, furniture, bedding, and car interiors thoroughly and throw the vacuum-cleaner bag away when finished.
Shampoo your hair regularly.
Keep any open sores clean.
Treatment of scabies
Treatment should involve the entire household, and any others who have had recent, prolonged contact with the infested individual.
Itches can be treated usingantihistamines and anti-inflammatory agents.
Bedding, clothing and towels used during the previous three days should be washed in hot water and dried in a hot dryer.
Permethrin, oral or tropical ivermectin is also prescribed.
Other treatments include; lindane, benzyl benzoate, crotamiton, malathion, and sulfur
Giuseppe Micali, Francesco Lacarrubba, Anna Elisa Verzì, Olivier Chosidow, Robert A. Schwartz. Scabies: Advances in Noninvasive Diagnosis. Published: June 16, 2016 http://dx.doi.org/10.1371/journal.pntd.0004691
Mary Harding. ‘Scabies’. Patient. 2014 .Web
Charles Patrick Davis. ‘Scabies’. eMedicineHealth 2016. Web.
FitzGerald, Deirdre; Grainger, Rachel J.; Reid, Alex (2014). “Interventions for preventing the spread of infestation in close contacts of people with scabies”.The Cochrane Database of Systematic Reviews.2: CD009943.doi:10.1002/14651858.CD009943.pub2. ISSN 1469 493X. PMID 24566946.