Current Perspectives on Erythema Multiforme

Recognition and timely adequate treatment of erythema multiforme remain a major challenge. In this review, current diagnostic guidelines, potential pitfalls, and modern/novel treatment options are summarized with the aim to help clinicians with diagnostic and therapeutic decision-making. The diagnosis of erythema multiforme, that has an acute, self-limiting course, is based on its typical clinical picture of targetoid erythematous lesions with predominant acral localization as well as histological findings. Clinically, erythema multiforme can be differentiated into isolated cutaneous and combined mucocutaneous forms. Atypical erythema multiforme manifestations include lichenoid or granulomatous lesions as well as lesional infiltrates of T cell lymphoma and histiocytes. Herpes simplex virus infection being the most common cause, other infectious agents like-especially in children-Mycoplasma pneumoniae, hepatitis C virus, Coxsackie virus, and Epstein Barr virus may also trigger erythema multiforme. The second most frequently identified cause of erythema multiforme is drugs. In different studies, e.g., allopurinol, phenobarbital, phenytoin, valproic acid, antibacterial sulfonamides, penicillins, erythromycin, nitrofurantoin, tetracyclines, chlormezanone, acetylsalicylic acid, statins, as well as different TNF-α inhibitors such as adalimumab, infliximab, and etanercept were reported as possible implicated drugs. Recently, cases of erythema multiforme associated with vaccination, immunotherapy for melanoma, and even with topical drugs like imiquimod have been described. In patients with recurrent herpes simplex virus-associated erythema multiforme, the topical prophylactic treatment with acyclovir does not seem to prevent further episodes of erythema multiforme. In case of resistance to one virostatic drug, the switch to an alternative drug, and in patients non-responsive to virostatic agents, the use of dapsone as well as new treatment options, e.g., JAK-inhibitors or apremilast, might be considered

The Impact of Institutions on Innovation

This paper studies the impact of radical institutional reform on innovation. We use the timing and geography of French invasions of different regions of Germany after the French revolution of 1789 as an exogenous shock to the institutions of those regions. German regions that were invaded by the French subsequently changed their institutions in important ways, including the introduction of the civil code, the dissolution of guilds, the abolition of serfdom and the implementation of agrarian reforms. These institutional changes in turn affect innovation. Using patents per capita as our measure of innovation, we show that counties whose institutions are more inclusive as a result of the French occupation also become more innovative. Moving from a county with no occupation to a county with the longest occupation, the implied changes in institutional reforms result in an increase of patents per capita of 123%. Our findings point to institutions as a first order determinant of innovation and highlight the role of innovation as a key mechanism through which institutions may foster economic growth