Scabies is one of the common dermatological problem which leads to skin disease. In developing countries are more prone to scabies infection while globally the disease can reach to almost 130 million individuals in a given time point. Although Scabies infection can develop anywhere, mostly in young and old individuals in developing countries, especially with low economic resources are more susceptible to it. Additionally, in presence of hot and tropical climate the rate of infection increases.
Scabies is formed by a small mite known as Sarcoptes scabiei. These tiny mites can burrow to the epidermis or outer skin layer, and eggs are laid by adult females. Within the period, the symptoms such as intense itching start as a result of mite proteins which can be found in feces. Intense itching further leads to accumulation of bacteria; especially two groups Staphylococcus aureus and Streptococcus pyogenes and develop skin sore or impetigo.
Impetigo also can produce complicated skin condition like abscess formation or sepsis, especially in infants. In tropical areas, the presence of Scabies infection may get involved with immune-mediated conditions like kidney disease-acute post-streptococcal glomerulonephritis or development of the rheumatic heart. A rare variation of Scabies is known as crusted scabies develops in immune-compromised patients with HIV or AIDS. In crusted scabies, mites in millions of numbers produce a large amount of scale and crust.
Diagnosis and Medication
Scabies mostly gets diagnosed by the presence of clinical features like severe itching, the appearance of small blisters forming thinly shaped irregular burrow in the skin, especially in finger web or insole. Itching for an extended period of times generates nodules which are seen mostly on the genital part.
Initial treatment option for scabies includes a local application of tropical scabicides creams such as permethrin 5% cream and malathion lotion 5% which is sold under the brand name Derbac M. Scabicides are affecting for killing both adult mites as well as eggs. However, the application of permethrin is not recommended for infants under six months of age. Malathion 5% is used within an aqueous base. In addition to these two medications, benzyl benzoate emulsion in 10-25% or 5–10% sulfur ointment is also used in Scabies management.
As a low-cost drug, benzyl benzoate or sulfur ointment is mostly used in developing countries. Scabicides are used in all areas of body covering neck to toe. Whereas in infants and young individuals additional application to head also as there are chances of scabies infection in head, scalp or face. Creams or lotions are applied and after specific time as instructed in the usage, it will be washed off. Although a single application of topical creams is recommended, however, a second dose, which can be applied 3-7 days after the first application is beneficial for the complete eradication.
As itching in scabies develops due to hyper-immune sensitivity, scabies symptoms can stay longer or re-appear even after the use of medicines. Addition to cream, now a day, ivermectin is taken orally, which is also a safe drug in respect to pregnant women and young children more than six years of age. Ivermectin application also shows improvement for as crusted scabies. In adults, its use of topical Ivermectin is only found in the USA, although not approves by FDA. To treat scabies complications like impetigo, antiseptics or antibiotics are used. For complete cure from Scabies infection treatment of all individuals present in the household is also recommended.
Prevention and control
As scabies can be spread quickly through skin contact, people living or working closely has a higher chance to get the infection. To avoid further spreading of Scabies infection some preventive measures can be taken, such as-
• Washing of clothes and bedding at a higher temperature (more than 50o), at the very first day of the treatment.
• In a situation, where washing is not possible, storage of cloths is recommended in a separate bag for three days until the death of the mites.
• Babies and children are required to prohibit from sucking hands, socks or mittens.
In some countries, management and control of Scabies have been identified as a priority in connection with public health. On a higher level of control measures, IACS or International Alliance for the Control of Scabies has been formed to work globally to control infection, spreading and reinfection. In addition to individual control, there is an increasing interest is evolving for the application of MDA or mass drug administration strategy.
To rule out the possibility, comparative studies are going on assessing ivermectin against the use of other topical creams. Further, to provide awareness, programs related to Scabies infection are getting included in current and on-going public health-related strategies.