Drug hypersensitivity reactions (DHRs) are typically classified into immediate and delayed reactions
based on the time interval between drug exposure and onset of symptoms. Clinical manifestations range from
mild to severe and life-threatening reactions. The most severe clinical entities are anaphylaxis and anaphylactic
shock for immediate reactions, and severe cutaneous adverse reactions such as Steven Johnson Syndrome and
Toxic Epidermal Necrolysis for delayed reactions. The diagnosis is complex and challenging, as drug provocation
tests and even skin tests can be very risky procedures, which makes them not recommended. Therefore, it is necessary
to search for useful early biomarkers to manage the diagnosis of these reactions. These biomarkers could
be useful to determine the clinical entity, but not to identify the culprit drug. Some of the currently available
biomarkers are few genetic associations of drug allergy with polymorphisms of human leukocyte antigen (HLA),
the detection of inflammatory and lipid mediators in serum, or the detection of cytokines, chemokines, and cytotoxic
markers in skin biopsies. In this literature review, it has been summarize the immunological mechanisms
involved in severe reactions, both immediate and delayed, and different early biomarkers: those currently used for
the diagnosis of these reactions as well as possible early biomarkers that could be useful with further studies to
standardize their clinical use.
By protecting against cutaneous inflammation, epidermal pigmentation provided an additional advantage for ancestral humans