Eritemas anulares en la infancia

Diffusive mediator feedbacks control the health-to-disease transition of skin inflammation

The spatiotemporal dynamics of inflammation provide vital insights into the understanding of skin inflammation. Skin inflammation primarily depends on the regulatory feedback between pro- and anti-inflammatory mediators. Healthy skin exhibits fading erythema. In contrast, diseased skin exhibits expanding erythema with diverse patterns, which are clinically classified into five types: circular, annular, arcuate, gyrate, and polycyclic. Inflammatory diseases with expanding erythema are speculated to result from the overproduction of pro-inflammatory mediators. However, the mechanism by which feedback selectively drives the transition from a healthy fading erythema to each of the five types of diseased expanding erythema remains unclear. This study theoretically elucidates the imbalanced production between pro- and anti-inflammatory mediators and prospective treatment strategies for each expanding pattern. Our literature survey showed that eleven diseases exhibit some of the five expanding erythema, thereby suggesting a common spatiotemporal regulation underlying different patterns and diseases. Accordingly, a reaction-diffusion model incorporating mediator feedback reproduced the five observed types of diseased expanding and healthy fading patterns. Importantly, the fading pattern transitioned to the arcuate, gyrate, and polycyclic patterns when the productions of anti-inflammatory and pro-inflammatory mediators were lower and higher, respectively than in the healthy condition. Further depletion of anti-inflammatory mediators caused a circular pattern, whereas further overproduction of pro-inflammatory mediators caused an annular pattern. Mechanistically, the bistability due to stabilization of the diseased state exhibits circular and annular patterns, whereas the excitability exhibits the gyrate, polycyclic, arcuate, and fading patterns as the threshold of pro-inflammatory mediator concentration relative to the healthy state increases. These dynamic regulations of diffusive mediator feedback provide effective treatment strategies for mediator production wherein skins recover from each expanding pattern toward a fading pattern. Thus, these strategies can estimate disease severity and risk based on erythema patterns, paving the way for developing noninvasive and personalized treatments for inflammatory skin diseases.

Figurate annulare erythemas

T. Colcott Fox (1849-1916) first introduced in 1889 the term "figurate erythemas." According to the clinical pattern, figurate erythemas are annular, circinate, concentric, polycyclic, or arciform. The most important figurate annulare erythemas are erythema annulare centrifugum, erythema marginatum, erythema gyratum repens, erythema migrans, erythema chronicum migrans, and the pediatric annular erythemas. Erythema annulare centrifugum might be due to fungal, bacterial, or viral infections or drugs. It tends to spread centrifugally while developing central clearing. The most common locations are the trunk and the proximal extremities. Individual lesions last from several days to weeks and may resolve spontaneously. Erythema marginatum is one of the criteria for the diagnosis of acute rheumatic fever, but it also might be seen as a symptom of other diseases such as hereditary angioedema with C1-inhibitor deficiency and psittacosis. The typical clinical picture is presented by serpiginous erythematous macules and plaques with central clearing and accentuated borders. Erythema gyratum repens is a figurate erythema associated with internal malignancy. It has been linked especially to lung, esophageal, and breast cancers. Erythema gyratum repens is characterized by multiple erythematous, rounded macules or papules, rapidly progressing and forming concentric bands with an unique wood-grained appearance with desquamation on the edges of the erythema. Erythema chronicum migrans is the most common sign of infection with Borrelia burgdorferi and other Borrelia species. It is characterized by a round or oval erythematous or livid macule with a central depressed or raised area on the spot of a previous tick bite. Erythema migrans grows centrifugally and slowly in a matter of days or weeks. Central clearing is observed in 60% of patients, thus forming a targetoid appearance of the lesion. Many other figurate erythemas can be observed in infancy (pediatric annular erythemas). To this group belong neonatal lupus, erythema gyratum atrophicans transiens neonatale, annular centrifugal erythema, familial annular erythema, annular erythema of infancy, eosinophilic annular erythema, and figurate neutrophilic erythema of infancy. The treatment of the various types of figurate erythemas should be etiologic, and when the underlying condition is addressed, the therapy usually is successful.

Urticaria vasculitis in a child: a case report and literature review

Annular urticarial lesions in a child must establish a main differential diagnosis with urticaria multiforme, common urticaria, acute hemorrhagic edema of infancy, erythema marginatum, erythema annulare centrifugum, annular erythema in childhood, erythema multiforme, Sweet's syndrome, Schönlein‐Henoch purpura, erythematosus lupus, several systemic vasculitis, and serum sickness.

Eosinophilic annular erythema in childhood - Case report

Eosinophilic annular erythema is a rare, benign, recurrent disease, clinically characterized by persistent, annular, erythematous lesions, revealing histopathologically perivascular infiltrates with abundant eosinophils. This report describes an unusual case of eosinophilic annular erythema in a 3-year-old female, requiring sustained doses of hydroxychloroquine to be adequately controlled.

Photodistributed erythema multiforme

Although the existence of photodistributed erythema multiforme has been recognized for years, few cases have been described to date. It is an uncommon, and probably underdiagnosed, skin disorder that can affect individuals of both sexes and all ages. It has been associated with drugs, reactivation of herpes simplex virus infection, and polymorphous light eruption. A diagnosis is made on the basis of history, physical examination, histology, and phototesting. The condition runs a benign, self-limiting course but patients may experience outbreaks for several years if the causative agent is not eliminated. It is treated symptomatically and patients are advised to avoid triggers and excessive sun exposure.