Annular lichenoid dermatitis of youth

Annular lichenoid diseases

Annular lichenoid diseases encompass a diverse range of pathologies that present as circular, raised, or flat lesions that may vary in size and number. Examples include annular lichenoid dermatitis of youth, annular lichen planus, erythema dyschromicum perstans, erythema multiforme, fixed drug eruption, lichen sclerosus, neonatal lupus, porokeratosis, subacute cutaneous lupus erythematosus, and lichenoid syphilis. Clinical morphology and histopathology can differentiate these entities.

Annular Lichenoid Dermatitis (of Youth)

About 20 years after its first description, Annular Lichenoid Dermatitis of Youth (ALDY) is recognized as a distinctive lichenoid dermatosis with specific clinical and histological features. The disease occurs mostly in young persons all over the world, runs a chronic course, and has an obscure etiopathogenesis. Clinically, lesions consist of persistent, asymptomatic erythematous macules and round-oval annular patches with a red-violaceous non-scaling border and central hypopigmentation, mostly localized on the groin and flanks. Histology shows a peculiar lichenoid dermatitis characterized by irregular epidermal hyperplasia with an alternation of thinned and quadrangular rete ridges and a dense band-like lichenoid infiltrate of lymphocytes in the papillary dermis. Typically, there is infiltration of lymphocytes into the lower epidermal layers with massive necrosis/apoptosis of keratinocytes, which is limited to the tips of rete ridges. Dermal lymphocytes are usually CD3⁺, CD4⁺, while most of the intraepidermal T cells are CD8⁺. Analysis of TCR-γ-chain gene rearrangement displayed polyclonality in all cases examined. Differential diagnosis mainly includes morphea, mycosis fungoides, annular erythemas and inflammatory lesions of vitiligo. Topical corticosteroids and topical tacrolimus represent the most effective drugs for ALDY treatment.

Uncommon non-infectious annular dermatoses

Several cutaneous diseases can present with annular lesions, making a distinction by physical appearance alone challenging. They can be distinguished into infectious and non-infectious, and common and uncommon annular dermatoses. Common non-infectious diseases include granuloma annulare, urticaria, and subacute lupus erythematosus. In addition, there are rare non-infectious non-neoplastic annular dermatoses whose nosographic attribution is established, including annually recurring erythema annulare centrifugum (EAC) and annular erythema in Sjögren syndrome and others whose nosographic positioning is still debated. They are neutrophilic figurate erythema, palpable migratory arciform erythema, eosinophilic annular erythema, and annular lichenoid dermatitis of youth. Their etiopathogenesis is largely unknown, although immune-mediated mechanisms are likely involved. It is difficult to establish if they are variants of reaction patterns or separate clinic-pathological entities. In fact, EAC and annually recurring EAC may represent different aspects of the same disease. Palpable migratory arciform erythema is hardly distinguishable from EAC deep type, Jessner-Kanof disease, and lupus tumidus. Neutrophilic figurate erythema and eosinophilic figurate erythema are clinically very similar and differing only in the relative proportion of eosinophils and neutrophils.

Annular lichenoid dermatitis of youth-Recurrent case of rare skin disease treated with cyclosporine

Annular lichenoid dermatitis of youth (ALDY), first described in 2003, represents an uncommon entity whose etiopathogenesis is still debated. Futhermore, the optimal treatment for ALDY is yet to be established. We report a 9-year-old girl who presented with annular and oval erythematous lesions mostly on her trunk, with several lesions on the neck, groin, flanks, and upper extremities. The lesions had histological and immunohistochemical features characteristic for ALDY. Treatment with H1-antihistamines, topical corticosteroid, and UVB therapy was unsuccessful, while systemic treatment with cyclosporine induced complete remission.

Mycosis fungoides in pediatric patients: Clinical features, diagnostic challenges, and advances in therapeutic management

Mycosis fungoides (MF) is the most common primary cutaneous lymphoma in pediatric patients. Given the indolent nature of MF, symptoms often present in childhood but may not be diagnosed as MF until adulthood. Delayed diagnosis is associated with poor long-term prognosis. Thus, increased clinician recognition and accurate diagnosis of early-stage MF in pediatric patients is critically important. In this review, we summarize the clinical features of the most common pediatric MF subtypes and highlight important differences between pediatric and adult MF. Moreover, we reviewed all pediatric MF case series published between 2008 and 2018 to analyze treatment modalities and identify emerging therapies. As treatment of pediatric MF is complex, selection of therapy varies significantly depending upon the specific clinical characteristics, disease severity, and patients' preferences.

[Skin biopsy of inflammatory skin diseases in childhood-when is it reasonable?]

Compared with adulthood, inflammatory skin diseases are relatively rarely biopsied in children. Apart from the invasiveness of the procedure, the required local anesthesia, and the risks of infection and scarring, the psychological trauma of the operation has a higher impact in childhood. If a biopsy is performed, expectations towards the dermatopathology report are high. However, the evaluation of biopsies taken from children is challenging for the dermatopathologist: on the one hand, because the biopsies are often tiny or just superficial shaves and, on the other hand, because criteria for evaluation have mostly been developed from findings in adult biopsy specimens. In children, the immune system is still in the process of maturation and, therefore, infiltrates in the skin may look different from those seen in adults; however, knowledge about that is very limited to date. Moreover, numerous rare genodermatoses may manifest themselves first in childhood and need to be considered in the differential diagnosis while experience with them is often limited. Starting from the clinical presentation, this article presents histopathological features of possible differential diagnoses in order to demonstrate the value or necessity of a skin biopsy in a pediatric patient. In addition, communication with parents and child, methods of local anesthesia and biopsy techniques will be considered.

Annular Lichenoid Dermatitis of Youth: A Chronic Case Managed Using Pimecrolimus

Annular lichenoid dermatitis of youth, first described in 2003, is a rare and occasionally chronic skin disease. We report a case of annular lichenoid dermatitis of youth relapsing over the course of 5 years successfully treated and maintained with topical pimecrolimus cream.

Cutaneous Pseudolymphomas

The term cutaneous pseudolymphoma refers to benign reactive lymphoid proliferations in the skin that simulate cutaneous lymphomas. It is a purely descriptive term that encompasses various reactive conditions with a varied etiology, pathogenesis, clinical presentation, histology, and behavior. We present a review of the different types of cutaneous pseudolymphoma. To reach a correct diagnosis, it is necessary to contrast clinical, histologic, immunophenotypic, and molecular findings. Even with these data, in some cases only the clinical course will confirm the diagnosis, making follow-up essential.

Annular Lichenoid Dermatitis of Youth: A Report of 2 Cases and a Review of the Literature

Annular lichenoid dermatitis of youth is a lichenoid dermatosis of unknown etiology. It mostly affects children and adolescents and has well-defined clinical and histological characteristics that permit a diagnosis. We present 2 new cases of annular lichenoid dermatitis of youth with classical clinical features in 2 girls, aged 2 and 4 years. The histologic findings, however, differed from those reported in the literature in that the lichenoid inflammatory infiltrate was located primarily at the top of the dermal papillae and not at the tips of the rete ridges. In both cases, the lesions regressed spontaneously without treatment.

Annular lichenoid dermatitis of youth: a separate entity or on the spectrum of mycosis fungoides? Case report and review of the literature

Annular lichenoid dermatitis (ALDY) is a rare dermatosis that is most often seen in children and young adults and is characterized by annular patches with raised borders, most frequently on the trunk and the groin. A distinct lichenoid tissue reaction involving the base of the rete, resulting in squared-off rete ridges, helps to differentiate this from other lichenoid dermatoses and mycosis fungoides (MF). Herein, we report an additional case of this condition in a 7-year-boy, whose biopsy exhibited the typical quadrangular rete alteration and also contained distinct aggregates of CD8+ lymphocytes, Langerhans cells and colloid bodies within the involved rete. A literature review with emphasis on the clinical and histopathological differential diagnosis reveals additional clinical features of ALDY to potentially help differentiate this entity from annular presentations of mycosis fungoides.