Papular Urticaria is also known as chronic gum-rash, infant purpura, infant prurigo. Papular Urticaria is the allergic dermatosis observed in children, mostly affected within the age from 3 month to 3 years old.
Etiology and pathogenesis are still unspecified, though the basic reasons include food allergy, environment (house dust, woolen and synthetic textile, toys, fur, floss, domestic animals, plants, etc.), insect bites, exposure to several medical products (iodine, bromine, sulfanilamides, antibiotics, amidopyrine, analgesics, and so forth). Among the pharmaceutical products, lately the reason of Papular Urticaria likely appears to be antibiotics. Furthermore, the significant importance of the etiological structure of this disease are gastrointestinal diseases, chronic center of infection, prophylactic immunization toxico-allergic after-effect of infectious diseases in the past.
Practically in all cases Papular Urticaria develops with the active form of exudative diathesis. The definitive skinned out element is the blister with the seropapula in the center, hard by touch, as the millet in size. Erythema and urticarial forms and bullous forms of papular urticaria are possible to occur (LA. Schteinshlucht, F.A. Zverkova, 1979). These are located on any cutaneous skin area, and seldom - in the face and pilary part of the head. Mucous coats are not affected. The appearance of skin rash look dynamic - in 6 to 12 hours the blister disappears with the seropapula left, then it resolves with some pigmentation on the affected area for some days. In many cases in the center of the papula there is serosanguineous crust instead of the vesicle that occurs due to scratching. The disease is described as being of recurrent run, with the strong paroxysmal itching, scratching, and mild polyadenopathy. The patients are irritant, anxious, whiny, they sleep unduly, suffer from anorexia, dyspeptic disorders, with eosinophilia identify by the total blood count, and anemia. The body temperature is within the normal range, though during the period of new rashes it increases to 37.5-38°C for the short-term period. The complications as impetigo often occur due to scratching.
Histopathology: acanthosis, intercellular and intracellular edema of belemnold layer with formation of tiny cavities in it with serous exudate; edema of the derma papillary layer, perivascular infiltration.