Cutaneous T-cell lymphoma

Non-Hodgkin lymphoma is a heterogeneous group of B-cell (about 85%) and T-cell lymphoid malignancies that spread noncontiguously and often involve extranodal sites, ranging from indolent follicular lymphoma to aggressive diffuse large B-cell lymphoma to highly aggressive Burkitt lymphoma. Diagnosis requires excisional or core biopsy with flow cytometry and cytogenetics, Ann Arbor staging with PET-CT, and treatment is subtype-specific, from observation to R-CHOP to intensive Burkitt regimens with aggressive tumor lysis and CNS prophylaxis.

Hodgkin lymphoma is a B-cell malignancy defined by Reed-Sternberg cells that classically presents with painless, contiguously spreading cervical or mediastinal lymphadenopathy in a young adult, and it is confirmed by excisional lymph node biopsy. Ann Arbor/Lugano stage and interim PET response drive risk-adapted ABVD chemotherapy with or without radiation, and most patients are cured.

Erythroderma (exfoliative dermatitis) is a severe, potentially life-threatening condition defined by diffuse erythema and scaling involving 90 percent or more of the body surface area, most often from flare of a pre-existing dermatosis such as psoriasis or atopic dermatitis, a drug hypersensitivity reaction, or an idiopathic process. Initial management centers on hemodynamic stabilization, fluid and electrolyte replacement, and warming, with low- to mid-potency topical corticosteroids for skin inflammation and systemic corticosteroids such as prednisone 0.5 to 1 mg/kg per day reserved for refractory idiopathic disease or a suspected drug reaction.

Psoriasis is a chronic, relapsing, immune-mediated dermatosis of accelerated keratinocyte turnover, classically presenting as sharply demarcated, silvery-scaled plaques on extensor surfaces, with guttate, inverse, pustular, and erythrodermic variants and an associated psoriatic arthritis. Mild-to-moderate disease is treated with emollients and topical corticosteroids with or without a vitamin-D analogue (calcipotriene 0.005% twice daily), while widespread (over 10% body surface area), recalcitrant, or severe disease escalates to phototherapy, methotrexate (weekly single dose 7.5 to 25 mg), or a biologic such as adalimumab, ustekinumab, or secukinumab, never a systemic glucocorticoid.

Atopic dermatitis is a chronic, pruritic, relapsing inflammatory skin disease of the face and flexural surfaces driven by a compromised skin barrier and an exaggerated immune response, often accompanying allergic rhinitis and asthma as part of the atopic triad. First-line treatment is fragrance-free emollients plus a topical glucocorticoid for active flares, escalating to topical calcineurin inhibitors, phototherapy, or systemic agents such as dupilumab for disease recalcitrant to topical therapy.

Graft-versus-host disease is a complication of allogeneic hematopoietic stem cell transplantation in which donor T cells attack recipient tissues, classically the skin, liver, and gut in the acute form and multi-organ fibrosis in the chronic form. Diagnosis is clinical, supported by biopsy, and management is prophylaxis with a calcineurin inhibitor plus methotrexate and treatment with corticosteroids, escalating to agents such as ruxolitinib for steroid-refractory disease.

Sepsis is life-threatening organ dysfunction caused by a dysregulated host response to infection, identified by an acute rise in SOFA score of 2 points or more in a patient with known or suspected infection. Survival depends on recognizing the pattern early and completing the hour-1 bundle: lactate, blood cultures before antibiotics, broad-spectrum antibiotics such as cefepime 2 g IV every 8 hours, and 30 mL/kg crystalloid for hypotension or a lactate of 4 mmol/L or higher.