Adverse cutaneous reactions to drugs are frequent, affecting 2% to 3% of all hospitalized patients. Fortunately, only about 2% of adverse cutaneous reactions are severe and very few are fatal.
...Stevens-Johnson syndrome and toxic epidermal necrolysis are severe life-threatening diseases with a mortality rate reaching 30%, and only prompt recognition and diagnosis, withdrawal of the offensive drug, and referral to an intensive care unit or burn care unit might improve the prognosis and save the patient's life.
Drug eruption with eosinophilia and systemic symptoms syndrome, formerly termed
drug hypersensitivity syndrome, is a rather distinct severe adverse drug reaction (ADR) characterized by eruption, fever, lymph node enlargement, and single or multiple organ involvement, with a high morbidity and a mortality rate of 10%.
These severe ADRs, together with serum sickness–like syndrome, are discussed in this review. Other severe reactions, such as anaphylaxis and vasculitis, are discussed elsewhere in this issue.
Although most of the readers, particularly those in the outpatient arena, will not be treating these patients, they are the ones who will see them first, diagnose them, realize the potential danger in their condition, and refer them to the appropriate treatment venue. Therefore, dermatologists should be familiar with these conditions and be prepared to handle them adequately.
Summary
Background
Indoleamine 2,3‐dioxygenase (IDO) is a tryptophan (TRP)‐catabolizing enzyme with regulatory effects on T cells. T cell inhibition is achieved through both TRP depletion and TRP ...metabolite accumulation in specific local tissue microenvironments. The expression of IDO activity by different types of antigen‐presenting cells (APCs) has been shown to play a role in many instances of immunoregulation and tolerance induction. Induction of IDO after the engagement of the high‐affinity receptor for IgE, FcɛRI, on atopic monocytes has been suggested to regulate T cell responses in atopic disorders. Interleukin‐10 (IL‐10), a cytokine known for its down‐regulatory functions in the immune system, has recently been associated with the stable expression of IDO in mature tolerogenic dendritic cells.
Objective
This study was devised to understand the role of systemic IDO and IL‐10 in the prevention of clinical apparent allergy.
Methods
The concentration of TRP and the break‐down product kynurenine were measured by high‐performance liquid chromatography in‐ and off‐season in sera from patients with seasonal allergic rhinitis (n=12) and from clinically asymptomatic atopic patients sensitized to specific aeroallergens (n=12). Non‐atopic (NA) individuals (n=12) served as control. The concentration of plasma IL‐10 was determined in parallel from these donors by ELISA in‐ and off‐season.
Results
In clinically unresponsive but aeroallergen‐sensitized atopic individuals significantly higher systemic activity of IDO and increased plasma IL‐10 levels were found during allergen exposure but not off‐season compared to symptomatic atopic individuals with allergic rhinitis and NA individuals.
Conclusion
Enhanced systemic IDO activity as well as increased systemic levels of IL‐10 may contribute to the containment of allergic T cell responses and could be involved in the maintenance of a state of clinical unresponsiveness.
Pemphigus vulgaris induced by radiotherapy Orion, E; Matz, H; Wolf, R
Journal of the European Academy of Dermatology and Venereology,
July 2004, Letnik:
18, Številka:
4
Journal Article
Recenzirano
ABSTRACT
Pemphigus can be triggered or induced by many insults, such as drugs, infections, viruses and neoplasms. X‐ray‐induced pemphigus has been recorded only rarely in the literature. We describe ...the case of a woman with pemphigus vulgaris in remission, who relapsed 1 week after completion of an irradiation course for breast cancer, in the exact location of the radiation. We review the previous 15 cases from the literature and outline the common features of those cases.
Summary A 68‐year‐old woman developed allergic contact dermatitis to topical metronidazole gel as proven by positive patch tests to the gel and to metronidazole. She was also allergic to ...methylchloroisothiazolinone and methylisothiazolinone (MC/MI). The similarity between the two molecules and the fact that the patient reacted to the gel after the very short incubation period of 1 day (i.e. not long enough for acquiring an active sensitization) makes the possibility of a cross‐reaction between these substances very plausible. As the isothiazolinones are widely used and comprise an important and relatively frequent cause of allergic contact dermatitis, a cross‐reactivity with metronidazole means that perhaps there should have been more cases of metronidazole allergy is more common than the current literature suggests.
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