Emerging treatments for pyoderma gangrenosum

The Clinical Chameleon of Autoinflammatory Diseases in Children

The very first line of defense in humans is innate immunity, serving as a critical strongpoint in the regulation of inflammation. Abnormalities of the innate immunity machinery make up a motley group of rare diseases, named ‘autoinflammatory’, which are caused by mutations in genes involved in different immune pathways. Self-limited inflammatory bouts involving skin, serosal membranes, joints, gut and other districts of the human body burst and recur with variable periodicity in most autoinflammatory diseases (ADs), often leading to secondary amyloidosis as a long-term complication. Dysregulated inflammasome activity, overproduction of interleukin (IL)-1 or other IL-1-related cytokines and delayed shutdown of inflammation are pivotal keys in the majority of ADs. The recent progress of cellular biology has clarified many molecular mechanisms behind monogenic ADs, such as familial Mediterranean fever, tumor necrosis factor receptor-associated periodic syndrome (or ‘autosomal dominant familial periodic fever’), cryopyrin-associated periodic syndrome, mevalonate kinase deficiency, hereditary pyogenic diseases, idiopathic granulomatous diseases and defects of the ubiquitin-proteasome pathway. A long-lasting history of recurrent fevers should require the ruling out of chronic infections and malignancies before considering ADs in children. Little is known about the potential origin of polygenic ADs, in which sterile cytokine-mediated inflammation results from the activation of the innate immunity network, without familial recurrency, such as periodic fever/aphthous stomatitis/pharyngitis/cervical adenopathy (PFAPA) syndrome. The puzzle of febrile attacks recurring over time with chameleonic multi-inflammatory symptoms in children demands the inspection of the mixture of clinical data, inflammation parameters in the different disease phases, assessment of therapeutic efficacy of a handful of drugs such as corticosteroids, colchicine or IL-1 antagonists, and genotype analysis to exclude or confirm a monogenic origin.

Pyoderma gangrenosum: a review of pathogenesis and treatment

INTRODUCTION

Pyoderma gangrenosum (PG) is a complex neutrophilic dermatosis that can occur as an idiopathic disease, in association with systemic conditions such as inflammatory bowel disease, as part of an inherited inflammatory syndrome. It can be challenging to treat, as it occurs in a wide variety of clinical settings and there is a lack of a standardized treatment approach. The main limitations to treatment have been an incomplete understanding of the pathogenesis. However, recent advances have been made in understanding the pathogenesis of this condition, and PG is now considered an autoinflammatory disease process. Areas covered: This review discusses the newest studies that further define our understanding of this disease and the relevant literature on treatment options for pyoderma gangrenosum. Expert commentary: The presence of abnormal neutrophils and T-cells lead to immune dysregulation, leading to lesions of PG. Increased levels of inflammatory mediators including IL-1β, IL-8, IL-17, and TNF-α contribute to the development of the disease but there are still several unknown factors, including the trigger for immune dysregulation and additional contributory components of the immune system. We provide our approach to the management of PG lesions, which involves a multi-faceted approach including wound care, topical therapy, and systemic medications in most cases.