Toxic Epidermal Necrolysis (TEN) stands as a severe skin reaction, forming a spectrum of diseases along with Stevens–Johnson syndrome (SJS). Among these, TEN emerges as the more severe counterpart. This condition manifests with early symptoms that include fever and flu-like manifestations, paving the way for a distressing progression. In a matter of days, the skin undergoes blistering and peeling, leading to the formation of painful raw areas. Mucous membranes, particularly in the mouth, are often affected, adding to the complexity of this severe skin disorder. Complications associated with TEN encompass dehydration, sepsis, pneumonia, and the ominous threat of multiple organ failure.
Causes and Risk Factors
The primary cause of TEN is often attributed to specific medications, notably lamotrigine, carbamazepine, allopurinol, sulfonamide antibiotics, and nevirapine. However, infections such as Mycoplasma pneumoniae and cytomegalovirus can also trigger this severe reaction. In some cases, the cause may remain elusive. Risk factors linked to TEN encompass HIV/AIDS and systemic lupus erythematosus.
Diagnosis and Classification
Diagnosing TEN involves a meticulous examination, with a skin biopsy being a crucial diagnostic tool. For TEN, more than 30% involvement of the skin is a defining factor. It is part of the spectrum of severe cutaneous adverse reactions (SCARs), along with SJS, an SJS/TEN overlap, and drug reactions with eosinophilia and systemic symptoms. Differentiation exists based on the extent of skin involvement, categorizing it as SJS (less than 10%), an intermediate form (10 to 30% involvement), and TEN.
Treatment and Prognosis
The management of TEN typically unfolds within a hospital setting, often in a specialized unit like a burn unit or intensive care unit. Efforts are directed at halting the causative agent, managing pain, and utilizing antihistamines. Additional interventions may include antibiotics, intravenous immunoglobulins, and corticosteroids. Despite these treatments, the course of the underlying disease typically remains unchanged. TEN, alongside SJS, affects approximately 1 to 2 persons per million per year, with a higher incidence in females. The typical onset is observed in individuals over the age of 40. While the skin usually regrows over two to three weeks, recovery can extend over months, often leaving survivors with chronic problems.
Signs, Symptoms, and Complications
TEN unfolds with a prodromal phase, resembling a flu-like illness with symptoms such as cough, runny nose, fever, decreased appetite, and malaise. The skin findings progress from red-purple macules to large blisters, ultimately leading to extensive skin involvement. Mucosal areas, including the mouth, eyes, and genitals, are frequently affected, causing pain and discomfort. Complications arising from TEN can persist long-term, affecting the skin, eyes, and mucosal surfaces.
Cause and Genetic Factors
Drug reactions contribute to the majority of TEN cases, with antibiotics, sulfonamides, beta-lactams, nonsteroidal anti-inflammatory drugs, and antiretroviral drugs topping the list. Certain genetic factors, such as specific HLA-types, are associated with an increased risk of TEN when exposed to specific drugs.
Pathogenesis and Diagnosis Advancements
The precise pathogenesis of TEN involves an overactive immune response, primarily by cytotoxic CD8+ T cells, leading to keratinocyte death and skin detachment. Early diagnosis is crucial, and ongoing research explores serum biomarkers like granulysin and high-mobility group protein B1 (HMGB1) for their potential in early detection.
To conclude, Toxic Epidermal Necrolysis is a complex and severe skin condition that demands prompt recognition and intervention. Understanding its causes, manifestations, and complications is pivotal in providing effective medical care to those affected.
