Asymmetric periflexural exanthema of childhood R21

Brunner et al. 1962

Self-limiting, 4-6 weeks lasting, probably infect-allergic skin disease of childhood.

Very rare occurrence. Mostly in individual children; occasionally in smaller epidemics.

A triggering agent is not yet known with certainty. The frequently described "asymmetry" of the skin symptoms is unusual. An infectious or parainfectious genesis in connection with previous viral infections (parovirus B19, parainfluenza 2 viruses, parainfluenza 3 viruses, Epstein-Barr viruses, adenoviruses/Cohen-Sors R et al. 2020, coronaviruses/Glick L et al. 2020; Valencia-Herrera A et al. 2023) is discussed.

Mostly in small children between 6 months and 10 years (average age: 2-3 years). Girls are more frequently affected than boys. The very rare occurrence in adults is described in individual cases. Seasonal accumulation of the occurrence in spring.

Thorax, usually beginning in the axillae, then spreading to one half of the trunk, but also upper extremity and buttocks. Occasionally also symmetrical infestation!

Mostly occurring after or during an infection with mild catharrhal or gastrointestinal symptoms (60% of patients), unilateral localized exanthema with maculo-papular, scaly inflammatory efflorescences, partly disseminated, partly following the Blaschko lines; occasionally also lichenoid skin changes; moderate pruritus (2/3 of cases); concomitant lymphadenopathy possible.

Nonspecific; gfls. positive viral serology.

Non-specific, superficial perivascular lymphocytic dermatitis with mild spongiosis and exocytosis

Tinea corporis; drug exanthema; acrodermatitis papulosa eruptiva infantilis (Gianotti-Crosti syndrome); pityriasis rosea, miliaria rubra

Make parents aware of the harmlessness of the disease pattern; also of the self-limiting course! Antihistamines for itching; bland-nursing external agents.

Benign course; healing of the exanthema after 3-6 weeks.

1. Bodemer C, Prost Y (1992) Unilateral laterothoracic exanthem in children: a new disease? J Am Acad Dermatol 27: 693-696
2. Brunner MJ et al (1962) A new papular erythema of childhood. Arch Dermatol 85: 539-540.
3. Cohen-Sors R et al (2020) Asymmetric periflexural exanthema of childhood and influenza virus infection. Dermatol Online J 26:13030/qt0qw93417.
4. Glick L et al (2020) "Unilateral laterothoracic exanthem in association with coronavirus disease 2019." JAAD case reports 6.9: 900-901.
5. Mc Cuaig C et al (1996) Unilateral laterothoracic exanthem. J Am Acad Dermatol 34: 979-984.
6. Peker S et al (2000) Unilateral laterothoracic exanthema. Case report and review of the literature. Dermatol 51: 505-508
7. Scott LA et al (2003) Viral exanthems. Dermatol Online J 9: 4
8. Strom K et al (1999) Unilateral latero-thoracic exanthema in childhood. Clinical characteristics and diagnostic criteria in 5 patients. Dermatologist 50: 39-44
9. Taieb A et al (1993) Asymmetric periflexural exanthema of childhood. J Am Acad Dermatol 29: 391-393.

10. Valencia-Herrera A et al (2023) Asymmetrical periflexural exanthema associated with SARS-CoV-2 infection in a pediatric patient. Acta Derm Venereol 103:adv00839.