Our data confirm that reducing Cr VI content of cement is useful in preventing allergic cement eczema, as previously found in Scandinavia. In contrast, the increasing prevalence of contact sensitization to epoxy resin components in the building trade is alarming. Preventive measures, which have already been implemented, have to be enforced.

Chlorhexidine is a widely used antiseptic and disinfectant. Compared to its ubiquitous use in medical and non-medical environments, the sensitization rate seems to be low. Multivarious hypersensitivity reactions to the agent have been reported, including delayed hypersensitivity reactions such as contact dermatitis, fixed drug eruptions and photosensitivity reactions. An increasing number of immediate-type allergies such as contact urticaria, occupational asthma and anaphylactic shock have been reported. In the case report, we describe anaphylaxis due to topical skin application of chlorhexidine, confirmed by skin testing and sulfidoleukotriene stimulation test (CAST(R): cellular antigen stimulation test). The potential risk of anaphylactic reactions due to the application of chlorhexidine is well known, especially that application to mucous membranes can cause anaphylactic reactions and was therefore discouraged. The use of chlorhexidine at a 0.05% concentration on wounds and intact skin was so far thought to be safe. Besides our patient, only one other case of severe anaphylactic reaction due to application of chlorhexidine on skin has been reported. Hypersensitivity to chlorhexidine is rare, but its potential to cause anaphylactic shock is probably underestimated. This review should remind all clinicians of an important potential risk of this widely used antiseptic.

During the last 20 years, the number of topical and systemic drugs for the treatment of acne vulgaris has been enriched. Topical drugs on the one hand have been newly discovered or further developments of already available agents such as in the group of retinoids or galenic formulation have improved efficacy or local tolerance. Topical retinoids are a mainstay in acne treatment since 1962. All-trans retinoic acid was the first and is still in use. Its irritative potential has led to the new galenics, i.e. incorporation in microsponges and in propolyomers, which increased the tolerability significantly. The isomer of tretinoin, isotretinoin, has the same clinical efficacy, but also a lower irritancy. A real breakthrough was adapalene, a retinoid-like agent, with a different retinoid receptor-binding profile, but in addition to the same clinical efficacy on inflammatory and non-inflammatory acne lesions compared to tretinoin, a better tolerability and, therefore, compliance. Unfortunately, over the past years topical retinoids have been less used in inflammatory acne than they should be, taking the the mechanisms of action into account. Topical antimicrobials, in particular topical antibiotics, should be used less often than in the past and only for short periods to avoid the development of resistances. It seems better to combine those agents with topical retinoids, with BPO or with azelaic acid to enhance the efficacy and slow down the development of resistance. BPO is still the gold standard for papular-pustular acne of mild-to-moderate type in concentrations of 2–5%. Azelaic acid is an alternative with efficacy on the comedo and is antibacterial without development of resistances. Finally, the physical removal by electrocautery or CO₂ laser of multiple densely packed closed comedones, macrocomedones and microcysts is necessary to enhance the efficacy of topical comedolytic agents and to speed up the therapeutic results. Photodynamic therapy has not yet been proven efficacious in controlled studies. Blue and red light can probably be used in association with local agents but enhancement of the irritative potential of topical and systemic agents has to be considered.

No abstract

The pathogenesis of acne, the most common skin disease, is complex and multifactorial. Clinical experience has demonstrated that parallel targeting of various pathogenetic factors, achieved either by mono- or combination therapy with appropriate drugs, represents the most effective approach to treating acne. Topical retinoids have been shown to expulse mature comedones, reduce microcomedone formation, and exert immunomodulatory effects. They have broad anti-acne activity without the risk of inducing bacterial resistance, which justifies their use as first-line treatment in most types of noninflammatory and inflammatory acne and makes them uniquely suitable as long-term medication to maintain remission after cessation of initial combination therapy. Systemic isotretinoin as a monotherapeutic agent strongly affects all four major pathogenetic factors and has been, in the hand of experienced dermatologists, a potent and safe agent for the treatment of severe and recalcitrant acne forms for more that 20 years. However, patient counseling, careful monitoring, and evaluation and management of adverse events are necessary. The use of isotretinoin has experienced a drawback now that its indication has been lowered from a first-line to a second-line medication.