Prurigo simplex acuta L28.22

A violently pruritic skin disease of childhood associated with urticarial papules, sometimes also with vesicles, occurring in episodes. Often there is a coexistence of different efflorescences. A counterpart in adults is not known. It should be noted that this clinical picture has nothing in common with adult prurigo except for the itching.

Insect bites, especially from arthropods such as mites and fleas, overall increased reactivity to exogenous factors Previously discussed: overfeeding of children (chocolate, jams), food allergy, adverse drug reaction, tooth eruption, stress.

In early childhood, usually occurring within the first 6 years of life, most frequently between the 2nd and 3rd month of life; seasonally clustered especially in spring and summer (peaking between May/June - Fleck M 1959) .

Especially extremities, trunk and buttocks are affected; the face is rather rarely affected, the hairy scalp is left out. The mucous membranes remain equally free.

Itchy, disseminated or grouped, barely lenticular, coarse, nonconfluent papules surrounded by a red, elevated halo; adjacent wheals up to the size of a fingernail.

Formation of central vesicles, erosions and crusts.

Rarely, large blisters(strophulus bullosus).

Frequently, the papules are scratched. Accordingly, lesional crust formation. Healing leaving a de- or hyperpigmented patch. Rarely, there are lesional scarring.

Since the course is episodic, a polymorphic picture may develop with older and fresh efflorescences.

Intraepidermal, often subcorneal, spongiotic vesicle, papillary edema. Lymphocytic, possibly also eosinophilic perivascular infiltrate.

Varicella: in contrast to varicella, there is no involvement of the capillitium and oral mucosa

Scabies: no duct structures detectable

Trombidiosis: infestation of the freely worn skin areas of tight-fitting clothing

Secondary infection.

It is important to treat pets, especially dogs, cats and birds. Dogs and cats can be safely treated with malathion (e.g. Organoderm solution), pyrethroids (e.g. Goldgeist forte) or pyrethrin (e.g. Spregal).

Repeat therapy at weekly intervals a total of 3 times. Ivermectin (300 μg/kg KG s.c.) is successful in animals.

Dispose of the animals' stock.

Disinfect the room.

Use of repellents.

Apply Lotio alba thinly, if necessary with addition of 1-5% Polidocanol R200 or 0.5% Hydrocortisone Gel R124 1-2 times daily. Exteriors containing crotamiton have also proved to be effective as lotio or gel (e.g. Eraxil Lotio, Crotamitex Gel).

In case of severe itching, a more moderate setting to an oral antihistamine such as desloratadine (e.g. Aerius syrup): children between 2 and 5 years of age: 2.5 ml once a day; children between 6 and 11 years of age: 5 ml once a day; adults and adolescents > 12 years of age: 10 ml once a day. Alternatively: Dimetinden ( e.g. Fenistil drops) children (1-8 years of age): 10-15 drops 3 times a day.

Recurrent or chronic course is possible. Usually the disease disappears between the 3rd and 5th year of life (M. Fleck 1959).

Originally, efflorescences were described as "seropapules". The exact definition of a seropapular is missing. This terminology can be dispensed with.

1. Dominguez-Amorocho O et al (2013) Differences in systemic and skin migrating-specific CD4 T cells in papular urticaria by flea bite. Int Arch Allergy Immunol 160:165-172
2. Fleck M (1959) Urticaria, strophulus angioneurotic edema, dermographism. In: Gottron HA et al. Dermatology and venereology. Georrg Thieme Verlag Stuttgart vol III/1 p 265.
3. Halpert E et al. (2017) Prevalence of papular urticaria caused by flea bites and associated factors
   inchildren 1-6 years of age in Bogotá, D.C. World Allergy Organ J 10:36.
4. Kar S et al (2013) Epidemiological study of insect bite reactions from central India. Indian J Dermatol 58:337-341
5. Manzotti G et al.(2011) Chronic papular urticaria due to pigeon ticks in an adult. Eur J Dermatol 21:992-993