The<unk>  of DRESS syndrome usually begin 2 to 6 weeks but uncommonly up to 8–16 weeks after exposure to an offending<unk> .<unk>  generally include fever, an often itchy rash which may be morbilliform or consist mainly of macules or plaques, facial edema (i.e. swelling, which is a hallmark of the disease), enlarged and sometimes painful lymph nodes, and other<unk>  due to inflammation-based internal organ involvement, most commonly liver, less commonly kidney, lung, and heart, and rarely pancreas or other organs. Laboratory findings include increased blood<unk> nd atypical lymphocyte counts, elevated blood markers for<unk>  inflammation (e.g. erythrocyte sedimentation rate, C-reactive protein), and evidence of internal organ involvement. Liver involvement is detected by measuring blood levels of alanine aminotransferase (ALT), a marker of hepatocyte injury, and alkaline phosphatase (ALP), a marker of bile duct injury, to define three types of injury: hepatocellular (elevated ALP, high ALT/ALP ratio of greater than 5), cholestatic (high ALP, low ALT/ALP ratio of less than 2), and mixed (elevated ALT and ALP, ALT/ALP ratio between 2 and 5, the cutoff values for cholestatic and hepatocellular injury, respectively). Renal involvement is more prone to occur in older individuals and in those with prior kidney or cardiovascular disease; it may take the form of severe interstitial nephritis, acute tubular necrosis, or vasculitis and may lead to kidney failure and, uncommonly, be lethal. Lung involvement takes the form of interstitial pneumonitis, pleuritis, or the acute respiratory distress syndrome; minocycline and abacavir are the main culprit<unk> s causing severe lung involvement. However, lung involvement in this disorder typically resolves. Cardiac involvement usually presents with evidence of left ventricular dysfunction and ECG changes; it occurs more often in individuals taking minocycline, ampicillin, or sulfonamides, and is either a cardiac hypersensitivity<unk>  classified as an<unk>  myocarditis which generally resolves or a far more serious acute necrotizing<unk>  myocarditis which has a mortality rate of more than 50%. Neurological manifestations of the DRESS syndrome include headache, seizure, coma, and motor dysfunction due to meningitis or encephalitis. Rare manifestations of the disorder include inflammation of the pancreas, gastrointestinal tract, and spleen. The following table gives the percentages for organ involvement and blood abnormalities found in individuals with the DRESS syndrome based on various studies. There are large variations in the percentages found in different studies and populations. Organ Percentage involvement comment Blood abnormality Percentage involvement Comment Liver 59-100% >90% if based on high blood levels of ALT<unk>  30-95% usually seen in >66% of cases Kidney 8-40% >40% if based on high levels of BUN or creatinine Atypical blood lymphocytosis 27-67% - Lung 5-33% usually resolves Lymphocytosis ~3% - Heart (hypersensitivity<unk>  2-15% generally not life-threatening Leukocytosis up to 100% due to<unk>  and/or lymphocytosis Heart (necrotizing<unk>  myocarditis) 2-15% mortality> 50% Thrombocytopenia 3% Thrombocytopenia may precede and not be due to DRESS syndrome Nervous system ~5% usually resolves Elevated ESR ~60-70% marker of<unk>  inflammation Pancreas ~5% may result in diabetes Elevated C-reactive protein ~60% marker of<unk>  inflammation No gold standard exists for diagnosis, and at least two diagnostic criteria have been proposed viz., the RegiSCAR criteria and the Japanese consensus group criteria. These two sets of criteria are detailed in the following table. RegiSCAR inclusion criteria for DRESS syndrome: 3 of the 4 starred criteria are required for diagnosis Japanese consensus group diagnostic criteria for DIHS: 7 criteria are needed for diagnosis of DIHS or the first 5 criteria required for diagnosis of atypical DIHS. Hospitalization pruritic, macular erythema containing papules, pustules or vesicles (generally a Maculopapular rash), developing >3 weeks after starting suspected<unk><unk>  suspected to be<unk> -related Prolonged clinical<unk>  2 weeks after discontinuation of the suspected<unk>  Acute Rash* Fever > 38 °C Fever > 38 °C* Liver abnormalities (ALT > 100 U/l) or other organ involvement Lymphadenopathy in at least two sites* Leukocyte abnormalities Involvement of at least one internal organ* Leukocytosis ( > 11 x 109/l) Blood count abnormalities (lymphopenia or lymphocytosis*,<unk> *, thrombocytopenia*) Atypical lymphocytosis (>5%) Severe nerve pain Lymphadenopathy Human herpesvirus 6 reactivation
Drug reaction with eosinophilia and systemic symptoms
Mast cell activation syndrome
Hypotrichosis–lymphedema–telangiectasia syndrome
Tropical eosinophilia
Leukotriene receptor antagonist-associated Churg–Strauss syndrome
Bare lymphocyte syndrome type II
Pitt–Hopkins syndrome
Papular purpuric gloves and socks syndrome