Phleboderma ( Latin Phlebotodermia ; mosquito dermatosis ) - entomosis , pruritic dermatosis common in hot countries, resulting from sensitization of the human body to the secretion of the salivary glands of Phlebotomus mosquitoes, is manifested by an itchy nodular rash.
| Phleboderma | |
|---|---|
 Mosquito Phlebotomus papatasi |
Content
Etiology and epidemiology
The causative agents are mosquitoes Phlebotominae (neg. Diptera ). Only females bite, obeying gonotrophic harmony , according to which oviposition is preceded by an act of bloodsucking.
The disease is common in hot climates, especially in the Middle East. It is found in Central Asia. In temperate countries, the disease is seasonal in nature (summer, autumn).
A predisposing factor are: helminthic invasion , malaria , some other tropical parasitic diseases [1] .
Clinical picture and pathogenesis
By the nature of the course of phlebotoderma, they are divided into acute and chronic.
In places of mosquito bites, spots of pale pink color appear, with point hemorrhage in the center, soon turning into towering whitish-pearly itchy papules, often with a small bubble on top.
Gradually, the papules condense and turn into pruriginous nodes, often covered with serous-bloody crusts, accompanied by biopsy itching and burning of the skin. Secondary pyococcal eruptions are frequent.
The course of the disease is long (1-6 months, up to several years).
Histological examination shows acanthosis and hyperkeratosis of the epidermis, in the dermis - diffuse infiltration of fibroblasts, degeneration of collagen, elastic fibers and often hyperplasia and dystrophy of the nerve bundles.
The clinical picture of phlebotoderma is characterized by the appearance of small (from 1 cm in diameter) edematous papules in open areas of the skin (the back of the hands, forearm, lower leg, face), which is accompanied by burning and mild itching. After repeated insect bites, papules can transform into more dense dermal-hypodermal nodes, and intense itching appears. Nodes can occur in closed areas of the body.
An immediate reaction to a mosquito bite is redness, blistering and itching. With a delayed reaction, edema and burning itching usually occur. An immediate reaction is often short-lived; a late one may last for several hours, days, or weeks. There are three types of hypersensitivity reactions: urticaria, tuberculin and eczemoid. Sometimes there is the Arthus phenomenon with skin necrosis. There is a seasonal increase in the reaction to a mosquito bite, while more pronounced edema and rashes can be accompanied by complications such as fever, general malaise, generalized edema, severe nausea and vomiting , as well as skin necrosis with subsequent scarring.
A complication of pustular skin diseases is possible (see Pyoderma ).
Mosquitoes , biting people, infect them with various vector-borne diseases , since these insects are specific carriers of the causative agents of phlebotomy fever and other arbovirus infections , cutaneous and visceral leishmaniasis , and bartonellosis .
Treatment
Phlebotoderma with knotty pruritus, urticaria, rashes caused by bites of fleas, bugs, ticks, and lice are differentiated (see Stings and insect bites ).
The treatment is carried out with hyposensitizing agents, B vitamins, autohemotherapy, antipruritic agents are used. In severe cases, corticosteroids are prescribed. With complications of pyoderma, antibiotics are prescribed.
The forecast is favorable.
Varieties
Harara (hararΠ°) is a seasonal multiforme urticaria , develops after repeated mosquito bites and is close to phlebotoderma with the flow; characterized by severe itching , papular vesicular, and subsequently dense nodular rashes on the limbs, face and trunk and a long course.
Moskitosis (moscitosis) - dermatosis caused by exposure to mosquito saliva during a bite, characterized by urticarial or papular eruptions.
Literature
Notes
- β Big Medical Encyclopedia, vol. 26, M. 1985, p. 340.