Scabies is a very contagious skin infection in young children, determined by the arthropod Sarcoptes scabiei. The way of transmission: through human contact. The term scabies is derived from Latin term ’’scabere’’meaning to scratch. The lesion caused by the female mite affect especially the corneum of the skin.
Pathophysiology:
The immune system reacts at the debris, feces and eggs left by the female mite in the burrows in the outer layer of the skin. The larvae mature to adult forms in 2 weeks time and continue the cycle, in her short life of one month the female mite lays up about 100 eggs. In the regular scabies the patient is infected with 10-15 adult female mites, but in other types of scabies there may be more mites. Pruritus is the main symptom appears secondary after the exposion to the mites and is due to the hypersensitive response The skin looks rashy with papules, vesicles, pustules and burrows. A study of the cellular infiltrate types and patterns in lesions of scabies have proved that cell T4 dominance is the cause of persistent itching and T8cells leads to improvement in the pruritus.
Frequency:
In the US scabies affects people of all ages, is a disease of overcrowding. Patients with immunodeficiency, HIV, or institutionalised present Norwegian scabies.
Mortality/Morbidity
Scabies may infest people of all ages and races, there is no special predisposition. Excoriations and secondary bacterial infections may appear due to the intense pruritus.
In establishing the diagnosis is important to watch for the history of involvment of family members, irritability and nocturn pruritus are sometimes the only symptoms.
Physical:
Primary lessions in scabies are: papules, rashes, vesicles, pustules.
Secondary lesions appear after scratching: crusted areas and excoriated papules.
In adults the lesions appear on the arms, wrists, spaces between the fingers, axillae, nipples, scrotum, penis, umbilicus. In infants the most affected areas are: the soles, palms, scalp, axillae.
Norwegian scabies
This type is highly contagious and may spread rapidly because there are many mites, hundreds of mites. Norwegian scabies lesions are generalized, the crusty lesions and plagues on feet, hands, scalp are hyperkeratosic.
Nodular scabies
Nodular scabies is another type of scabies different from the Norwegian and regular one because of the pathognomonic orange red nodules in the axillae and groin. To ensure the best treatment it is vital to know exactly the symptoms of scabies and to identify them in order to prevent the infestation in community. Scabies infects only humans and can survive only for 1-4 days out of the human body, pets do not get infested with scabies. Often it may be confused with other skin infections such as: eczema, impetigo especially in young children.
By: Groshan Fabiola