Cutaneous Langerhans cell histiocytosis: The spectrum of a rare cutaneous neoplasia

Diaper dermatitis-a narrative review of clinical presentation, subtypes, and treatment

Diaper dermatitis (DD) is an umbrella term with different clinical presentations, pathophysiology, treatments, and outcomes. The major subtypes include irritant contact dermatitis and candida-associated DD. In case of atypical presentation or unresponsiveness to treatment, other differential diagnoses should be considered. Although DD can occur at any age, it peaks in newborns and infants < 2 years of age. We will focus on this age group in our narrative review.

Childhood Langerhans cell histiocytosis: a disease with many faces

BACKGROUND

Langerhans cell histiocytosis (LCH) is a group of diseases characterized by the proliferation and accumulation of Langerhans cells. Clinical presentations of LCH vary widely.

DATA SOURCES

A PubMed search was conducted using Clinical Queries with the key term "Langerhans cell histiocytosis". The search strategy included meta-analyses, randomized controlled trials, clinical trials, observational studies, and reviews. This paper is based on, but not limited to, the search results.

RESULTS

Generally, patients with LCH can be divided into two groups based on the extent of involvement at diagnosis, namely, single-system LCH and multisystem LCH. The involvement may be unifocal or multifocal. Patients with isolated bone lesions typically present between 5 and 15 years of age, whereas those with multisystem LCH tend to present before 5 years of age. The clinical spectrum is broad, ranging from an asymptomatic isolated skin or bone lesion to a life-threatening multisystem condition. Clinical manifestations include, among others, "punched out" lytic bone lesion, seborrheic dermatitis-like eruption, erythematous/reddish-brown crusted/scaly papules/maculopapules/plaques/patches, and eczematous lesions, diabetes insipidus, hepatosplenomegaly, cytopenias, lymphadenopathy, and an acute fulminant disseminated multisystem condition presenting with fever, skin rash, anemia, thrombocytopenia, lymphadenopathy, and hepatosplenomegaly. The diagnosis is clinicopathologic, based on typical clinical findings and histologic/immunohistochemical examination of a biopsy of lesional tissue. Positive CD1a, S100, and/or CD207 (Langerin) immunohistochemical staining of lesional cells is required for a definitive diagnosis. Watchful waiting is recommended for patients with skin-only LCH. Patients with symptomatic or refractory skin-only LCH may be treated with topical tacrolimus/corticosteroids, topical nitrogen mustard, oral methotrexate, or oral hydroxyurea. The current recommended first-line therapy for patients with multisystem LCH is 12 months therapy with prednisone and vinblastine. Mercaptopurine is added for patients with risk organ involvements.

CONCLUSIONS

Because of the broad spectrum of clinical manifestations and the extreme diversity of disease, LCH remains a diagnostic dilemma. Morphological identification of LCH cells and positive immunochemical staining with CD1a, S100, and/or CD207 (Langerin) of lesional cells are necessary for a definitive diagnosis.

The color of skin: yellow diseases of the skin, nails, and mucosa

The colors reflected from the skin are important indicators of dermatologic and systemic disorders. Incident light is subject to absorption by chromophores in the skin and scattering. Chromophores associated with yellow light reflection include the carotenoids and bilirubin. Various pathophysiologic mechanisms associated with these and other chromophores manifest with a yellow hue on examination. This review describes these mechanisms and the clinical features of yellow skin disorders by morphology. A brief summary of the differential diagnosis, laboratory investigations, and treatments are presented. Yellow skin disorders are a heterogenous group composed of abnormalities in keratin, elastic and connective tissue, lipid metabolism, and other states of metabolic, inflammatory, or organ dysfunction. Patients will present through different routes, and skin disease may precede or follow systemic disease. Dermatologists have an essential role in identifying those with malignant or systemic associations to ensure early diagnosis and treatment.

Diverse cutaneous manifestation of Langerhans cell histiocytosis: a 10-year retrospective cohort study

Cutaneous manifestation is a common presentation of LCH and is usually a leading clue for the disease diagnosis. Having cutaneous lesions did not show a significantly early age onset at diagnosis compared to those without skin lesions, P value = 0.71. In the present study, cutaneous findings were found as 77.7%. Seborrheic dermatitis-like lesions were the most common cutaneous type (42.8%), followed by papules/nodules/masses (28.5%), petechiae/hemorrhagic lesions (17.8%), and eczematous lesions (10.7%). Time to diagnosis of LCH presented with seborrheic dermatitis-like lesions was significantly longer than other cutaneous presentations, P value = 0.0011.Conclusion: Patients with LCH who had the manifestations of seborrheic dermatitis-like lesions can have diagnosis delayed due to the difficulty in distinguishing these lesions from normal seborrheic dermatitis lesions. Petechiae/hemorrhagic cutaneous signs in addition to the normal seborrheic dermatitis is the clue for early detection of the disease. To improve early detection of LCH, general pediatricians should be alerted to be aware of these skin symptoms, and if they persist, a dermatologist, pediatric if available, should be immediately consulted. What is Known? • Cutaneous manifestation is a common presentation of LCH and is usually a leading clue for the disease diagnosis. What is New? • Patients with LCH who have the manifestations of seborrheic dermatitis-like lesions can have a delayed diagnosis due to the difficulty in distinguishing normal from seborrheic dermatitis lesions. • Petechiae/hemorrhagic cutaneous signs in addition to the normal seborrheic dermatitis are the clue to the early disease detection.

Diffuse Normolipemic Plane Xanthoma (DNPX) of the Neck without Xanthelasma Palpebrum

Diffuse normolipemic plane xanthoma (DNPX) is an uncommon subtype of non-Langerhans histiocytosis. DNPX is characterised by xanthelasma palpebrarum, diffuse plane xanthoma of the head, neck, trunk, or extremities, and normal plasma lipid levels. The neck is the most common site. We report about a 62-year-old female Caucasian patient, who developed an asymptomatic fine wrinkling and loose skin on the neck and décolleté about three years ago. The skin colour became yellowish. Xanthelasma was absent. Histopathology of a skin biopsy confirmed the diagnosis of DNPX. The patient had a medical history of chronic myeloblastic leukaemia. No other laboratory abnormalities were found. Laser treatment was offered but opposed by the patient.