How to manage infections in the era of biologics?

ABSTRACT:   Biologic agents are immunosuppressants that target cytokines or specific immune cell subpopulations. Many therapies interfere with the normal inflammatory cascade and with the immune system, causing an increase in the incidence of infections. In particular, treatment with tumor necrosis factor (TNF)-α antagonists in psoriasis patients is associated with an increased risk of infection caused by intracellular microorganisms. TNF-α plays an important role in host resistance against infectious and several cases of Mycobacterium tuberculosis , Listeria monocytogenes , and Pneumocystis carinii have been reported with anti-TNF-α agents. Furthermore, B and T cells are essential to the immune response; thus, their specific reduction or inhibition by targeting molecules in T-cell cutaneous lymphomas and psoriasis could increase the risk for viral, fungal, and bacterial infections. A prompt and appropriate management of infections with the emergence of biologics is essential in clinical practice.     

Cutaneous hypersensitivity reactions to freshwater cyanobacteria – human volunteer studies

Background

Pruritic skin rashes associated with exposure to freshwater cyanobacteria are infrequently reported in the medical and scientific literature, mostly as anecdotal and case reports. Diagnostic dermatological investigations in humans are also infrequently described. We sought to conduct a pilot volunteer study to explore the potential for cyanobacteria to elicit hypersensitivity reactions.

Methods

A consecutive series of adult patients presenting for diagnostic skin patch testing at a hospital outpatient clinic were invited to participate. A convenience sample of volunteers matched for age and sex was also enrolled. Patches containing aqueous suspensions of various cyanobacteria at three concentrations were applied for 48 hours; dermatological assessment was made 48 hours and 96 hours after application.

Results

20 outpatients and 19 reference subjects were recruited into the study. A single outpatient produced unequivocal reactions to several cyanobacteria suspensions; this subject was also the only one of the outpatient group with a diagnosis of atopic dermatitis. No subjects in the reference group developed clinically detectable skin reactions to cyanobacteria.

Conclusion

This preliminary clinical study demonstrates that hypersensitivity reactions to cyanobacteria appear to be infrequent in both the general and dermatological outpatient populations. As cyanobacteria are widely distributed in aquatic environments, a better appreciation of risk factors, particularly with respect to allergic predisposition, may help to refine health advice given to people engaging in recreational activities where nuisance cyanobacteria are a problem.     

Psoriasis: to treat or to manage?

The recognition of psoriasis as a systemic disorder with characteristic skin symptoms and associated diseases has changed treatment concepts substantially. The complexity of psoriasis disease not only requires appropriate therapy but also weight‐loss and smoking cessation programmes as well as trigger factor elimination. The term ‘management’ may better reflect the aim for a holistic approach of disease control. Comorbidity and the presence of psoriatic arthritis are important denominators for drug selection. However, there is a lack of prospective data substantiating a benefit of associated diseases by antipsoriatic therapy. Securing success using treatment goals helps to establish an efficacious therapy and to control inflammation. A regular scoring of disease severity, patients’ quality of life and assessment of other clinically relevant conditions are mandatory to closely follow the disease course. There is debate whether an early treatment may modulate the future course of psoriasis. Concepts of minimal disease activity have not been implemented in psoriasis yet. There is a lack of evidence how long any treatment should be given and when and how to terminate. Finally, outcome tools should specifically be tailored for psoriasis to evaluate disease‐related items as well as the benefit of management from the patient's perspective.     

Patch,prick or intradermal tests to detect delayed hypersensitivity to corticosteroids?

Background. Contact allergy to topical corticosteroids is usually detected by patch testing. Objectives. This study compares the test results obtained with patch, prick and intradermal testing, to assess the most sensitive method for diagnosing corticosteroid hypersensitivity. Patients/Methods. Nineteen corticosteroid‐allergic subjects and three control subjects were included. Patch, prick and intradermal tests were performed with five commercial corticosteroid preparations, as well as with the respective active principles diluted in ethanol. The test readings were performed at different time points, i.e. at 8, 24, 48 and 96 hr, and at 7 days. Results. Patch tests with ethanolic preparations produced more positive reactions than the commercial ones. The intradermal tests became positive earlier than the patch tests, a concordance between patch and intradermal tests being found in 11/15 (two positive intradermal test results with negative patch test results and vice versa). However, several subjects developed skin atrophy (14/22) at intradermal injection sites. Conclusion. Patch testing with the active principles diluted in ethanol remains the diagnostic method of choice for the detection of delayed hypersensitivity to corticosteroids. Intradermal tests with late readings, despite detecting additional contact allergy cases, should not be routinely performed, because of an important risk of atrophy, particularly with corticosteroid suspensions.     

How to define chronic prurigo?

Chronic prurigo impairs quality of life and is immensely challenging to treat. Until recently, no clear definition or classification system was available for this disease. A European task force specialized in pruritus defined chronic prurigo as a distinct disease characterized by chronic pruritus, a lengthy scratching behaviour and the presence of pruriginous lesions. Papular, nodular, plaque, umbilicated and linear prurigo were identified as clinical subtypes according to the most prominent lesion type observed in the physical examination. Various clinical and pathophysiological aspects, which are common across the range of clinical manifestations of chronic prurigo, argue for chronic prurigo as a disease in its own right. Chronic prurigo should be clearly demarcated from other conditions such as so‐called acute or subacute prurigo forms as well as from psychogenic self‐inflicted skin lesions, since different diagnostic criteria apply for these diseases. This viewpoint essay provides a detailed definition and classification of chronic prurigo including its obligatory and associated diagnostic criteria and discusses chronic prurigo as a distinct disease as well as the demarcation to other relevant conditions.     

Type I hypersensitivity in an asthmatic child allergic to peanuts: was soy lecithin to blame?

BACKGROUND: Soy lecithin is widely used as an emulsifier, not only in topical skin care products but also in various drugs administered either topically, orally, or intravenously or by inhalation. Patients strongly allergic to soy and/or peanuts can develop an anaphylactic reaction when exposed to soy lecithin. METHOD: We report a 3-year-old asthmatic boy, allergic to peanuts, who was treated at the emergency department for an exacerbation of asthma following an upper respiratory tract infection. Within an hour after receiving the second of two inhalations of an ipratropium bromide (Atrovent) metered dose inhaler, he developed respiratory distress and generalized urticaria, an adverse event that regressed within 48 hours of withdrawal of the suspected drug. Soy lecithin, contained as an excipient in the metered dose inhaler, was strongly suspected of being responsible for this reaction. CONCLUSION: Drug products containing soy lecithin can cause severe allergic reactions in patients allergic to peanuts or soy. Physicians should be aware that adverse drug reactions can be due to both the active medical component and the excipient ingredients.