Educational Posts

Alopecia areata (AA) is a nonscarring autoimmune disorder characterizedby a T-cell-mediated attack on anagen hair follicles, resulting in abrupt hair loss without permanent follicular destruction. The lifetime risk is approximately 2%. Recent epidemiologic data demonstrate racial differences in disease prevalence, with the highest rates observed among Asian (414 per 100,000) and Black (226 per 100,000) individuals compared with White individuals (168 per 100,000). Although ge

Tinea capitis is a dermatophyte infection of the scalp hair caused primarily by Trichophyton and Microsporum species. The fungi invade keratinized tissue, including the hair follicle and hair shaft, leading to brittle hair, scaling, and alopecia. Tinea capitis most commonly affects children, particularly those between three and 14 years of age, although adult cases can occur. In adults, tinea capitis infection is uncommon but has been reported most often in postmenopausal wom

Central centrifugal cicatricial alopecia (CCCA) is a lymphocyte-predominant scarring alopecia characterized by permanent hair loss that classically begins on the crown of the scalp and gradually spreads centrifugally. It predominantly affects women of African descent, with estimates suggesting a prevalence of up to 7%. However, no population-based studies have been performed, so its true prevalence remains unknown. CCCA is believed to result from a complex interplay of geneti

Psoriasis is a chronic inflammatory dermatosis that presents with important clinical differences in individuals with darker skin tones. In a large cross-sectional study of more than 6,000 adults in the United States, the overall prevalence of psoriasis was estimated at 1.9 percent. Although prevalence was lower among individuals with darker Fitzpatrick skin types, these patients experienced greater disease severity and quality-of-life burden. This disparity may reflect delaye

Lichen planus (LP) is a chronic, inflammatory dermatosis characterized by T cells targeting basal keratinocytes because of dysregulated cell-mediated immunity, with associations including viral infections, medications, contact allergens, and autoimmune conditions. In individuals with darker skin tones, hypertrophic, pigmentosus, and actinic variants of lichen planus are observed more frequently, suggesting that environmental and pigmentary factors may influence disease expres

Seborrheic dermatitis (SD) is a chronic inflammatory dermatosis affecting sebaceous-rich areas and is among the five most common dermatologic diagnoses in Black individuals. In the general population, SD affects approximately 5 percent of individuals; however, prevalence is higher among African Americans, estimated at 6.5 percent. Skin lipids and colonization with Malassezia species plays a role in disease pathogenesis, with downstream inflammatory effects that can be more pr

Contact dermatitis (CD) is an inflammatory skin disorder caused by exposure to external substances. CD is broadly classified into irritant contact dermatitis (ICD) and allergic contact dermatitis (ACD ) . ICD results from direct chemical injury to the skin followed by the release of inflammatory mediators from epidermal cells. ACD is a type IV delayed hypersensitivity reaction mediated by T cells. Overall, CD is more frequently reported in women, likely due to higher expos

Molluscum contagiosum is a common cutaneous viral infection caused by a DNA poxvirus and is frequently encountered in children and adolescents. Incidence increases during adolescence due to closer skin-to-skin contact, participation in athletics, shared equipment, and shaving practices. The virus infects epidermal keratinocytes, leading to the formation of characteristic dome-shaped papules. Lesions may persist for several months before spontaneous resolution occurs as cell-

Tinea versicolor, also known as pityriasis versicolor, is a superficial fungal infection caused by Malassezia species that commonly affects adolescents due to increased sebum production, physical activity, and humid environmental exposure. Malassezia organisms are part of normal skin flora but convert from their yeast form to their pathogenic hyphal form when exposed to heat, occlusion, and sweat. This transition leads to overgrowth within the stratum corneum and disrupts no

Acne vulgaris is a chronic inflammatory disease of the pilosebaceous unit and remains one of the most common dermatologic conditions in adolescence, affecting over 80% of teenagers. The pathogenesis is multifactorial. During puberty, sebaceous glands become increasingly sensitive to rising androgen levels, which stimulate excess sebum production and promote follicular obstructions. Additional contributing factors include the use of steroids, ultraviolet exposure, mechanical o

Atopic dermatitis, commonly referred to as eczema, is a chronic, relapsing, pruritic inflammatory skin disorder. The etiology of atopic dermatitis is complex and multifactorial. Although the exact mechanism is unknown, it is believed that AD arises from an interplay of epidermal barrier dysfunction, immune dysregulation and microbiome alterations. Additionally, genetic predispositions, such as loss-of-function mutations in the filaggrin gene, may set the stage for the immune-

Infantile hemangiomas are common benign vascular tumors of infancy that between 4-5% of infants, making it the most common infantile tumor. It arises due to an abnormal proliferation of endothelial cells and vascular networks, likely driven by factors such as hypoxia, aberrant stem cell activation, and dysregulated signaling pathways. The progression of infantile hemangiomas is classically biphasic. There is first a proliferative phase that is typically up to 3–5 months, foll

Neonatal herpes simplex virus (HSV) infection, sometimes referred to as “congenital HSV” when acquired in utero, is a serious viral disease that typically presents within the first 6 weeks of life. Transmission is most often peripartum, though a minority, < 5–10%, of cases may represent in utero (congenital) infection with transplacental spread. After exposure, the virus replicates and disseminates manifesting in one of three overlapping syndromes: SEM disease (skin, eye, m