Langerhans cell histiocytosis

Langerhans cell histiocytosis (LCH) are rare group of disorders due to the abnormal reproduction and accretion of dendritic cells in various tissues and organs which primarily affects children but also found in adults (Miro et. al., 2018). LCH ranges from a single bone lesion to the involvement of most organ systems which involves bone marrow, liver, spleen, lungs, and the central nervous system. Miro et. al aims to direct this journal towards two specific cases where both have hypopigmented macules as an initial presentation or symptom of LCH. Case 1 presented a 5-month-old African American boy with hypopigmented macules visible on his scalp, chest, abdomen, back, extremities, groin, and buttocks. When viewed under the microscope, there is a prominent band-like permeate of atypical Langerans cells filling the papillary dermis extending to the overlying epidermis. Case 2 showcases a 10-month-old African American girl with rashes on her neck, groin, and axillary regions who was diagnosed by her pediatrician with eczema and yeast infection. She, too, has hypopigmented macules on her back and posterior scalp including inguinal folds with pink papules coalescing into erosive plaques or commonly known as rashes.

LCH, then, results from the clonal proliferation of CD207+ myeloid dendritic cells which can be based on identification of characteristic CD1a, S100, or Langerin (CD207+; mononuclear cells. This disease can be classified according to the extent of organ involvement: single system which involves one organ system such as the skin, bone, or lungs which can be further categorized according to being unifocal and multifocal and multisystem that involves two or more organ systems. Manifestations mentioned of LCH in this journal was erythematous or reddening, scaling rash on the scalp and bent or curved areas similar to that of seborrheic dermatitis. Hypopigmented presentations then indicate a better prognosis. As for the treatment, children diagnosed with LCH were treated with vinblastine which is an anti-cancer chemotheraphy drug and prednisone or an oral synthetic corticosteriod when it reaches further than the cutaneous layer. Whilst, infants diagnosed with cutaenous LCH requires close observation with follow-up assessment regarding the development of multisystemic diseases. In conclusion, hypopigmented macules are the only presentation of LCH with older lesions regresses with time and contain no or very few identifiable Langerhans cells.