Severe atopic dermatitis in early infancy: characteristics, challenges and new perspectives in clinical practice.

Atopic dermatitis (AD) is the most common skin disease in infants and children with a prevalence of 10% in the first two years of life. In this age group up to 15% are severely affected. "Children are not little adults" - this applies in particular to infants with severe atopic dermatitis. Age-specific clinical aspects (psychosocial, neurocognitive, morphological) of the disease require an adjusted disease management. Considering recent approval of systemic treatment options, early identification of infants and children with severe and early persistent disease is of particular importance also in view of possible prevention of atopic comorbidity. As several inborn errors of immunity (IEI) share features of the atopic phenotype, it is essential for clinicians to distinguish signs of immunodeficiency from severe AD. Here, we describe a practical approach on the basis of clinical history and key dermatological and laboratory findings. Furthermore, this paper is aimed at providing an update on general management of severe AD in early infancy, including recommendations for systemic treatment.

Wells syndrome.

A rare eosinophilic dermatosis, Wells syndrome, also referred to as eosinophilic cellulitis, is characterized by great clinical variability. Typical findings include infiltrated erythematous plaques arising on the extremities. Lesions initially resemble erysipelas/cellulitis, however, they do not improve with antibiotic treatment. Eosinophilic cellulitis is a diagnosis of exclusion that may only be made over the course of the disease, taking into account clinical and characteristic histological findings (flame figures). Although multiple potential triggers have been proposed, the exact etiology remains unresolved. Involvement of abnormal Th2 cells, IL-5, and activated eosinophilic granulocytes suggest a nonspecific hypersensitivity response to exogenous or endogenous stimuli. Corticosteroids may have a beneficial effect on the chronic, recurrent course frequently observed. The disease is often self-limiting, healing without sequelae. Given that transitions to hematological and oncological disorders have been observed, patients should be closely followed up.

Wells-Syndrom.

Das Wells-Syndrom, auch als eosinophile Zellulitis bezeichnet, ist eine seltene, sporadisch auftretende eosinophile Dermatose mit polymorphem klinischem Bild. Als typisch gelten entzündliche Erytheme oder Plaques an den Extremitäten, die initial als Erysipel imponieren können, unter antimikrobieller Behandlung aber persistieren. Die eosinophile Zellulitis ist eine Ausschlussdiagnose, die in Zusammenschau von klinischem Befund und charakteristischem histologischem Bild (Flammenfiguren) nur im Verlauf gestellt werden kann. Mit einer Vielzahl möglicher Triggerfaktoren ist die Ätiologie nicht geklärt. Die Beteiligung abnormer Th2-Zellen, des Zytokins IL-5 und aktivierter eosinophiler Granulozyten lässt eine unspezifische Hypersensitivitätsreaktion auf exo- und endogene Stimuli vermuten. Die häufiger vorkommenden chronisch- rezidivierenden Formen lassen sich durch Glukokortikoide günstig beeinflussen. Der Verlauf ist meist selbstlimitierend, ohne Residuen. Aufgrund von Übergängen in hämatoonkologische Erkrankungen sind Verlaufskontrollen angezeigt.