Clinical images: steroid-induced chemical synovitis

Acute inflammation produces a coordinated set of local and systemic changes that limit injury, eliminate pathogens, and initiate repair. These responses arise within minutes of infection, trauma, or chemical insult and are driven by vascular alterations and leukocyte-derived mediators. When the stimulus resolves, the reaction typically abates within days.Local EffectsAt the site of injury, arteriolar vasodilation increases blood flow, resulting in redness and warmth. Simultaneously, increased...

Inflammatory bowel disease (IBD) encompasses two major chronic disorders—ulcerative colitis and Crohn’s disease—each characterized by relapsing episodes of gastrointestinal inflammation. Although they share certain clinical features, their patterns of involvement and manifestations differ in ways that aid diagnosis and guide management.Ulcerative ColitisUlcerative colitis is limited to the colon and rectum and involves continuous inflammation of the mucosal layer. The disease course is marked...

Glucocorticoids, a class of anti-inflammatory drugs, are pivotal in treating moderate to severe Crohn's disease by inducing remission. They exhibit their anti-inflammatory action by inhibiting the production of inflammatory cytokines such as tumor necrosis factor (TNF)-α, interleukin (IL)-1, and chemokines like IL-8. In addition, they reduce the expression of inflammatory cell adhesion molecules and inhibit gene transcription of nitric oxide synthase, phospholipase A2, cyclooxygenase-2 (COX-2),...

Spasmolytic agents are drugs used to alleviate muscle spasms and spasticity. They can be categorized into different chemical groups based on their mechanisms of action. Centrally acting spasmolytics primarily affect the spinal cord, while others directly target skeletal muscle cells.
A major class of centrally acting spasmolytics is the α2-agonist, such as tizanidine. These drugs bind to α2-adrenoceptors, inhibiting the release of the excitatory neurotransmitter glutamate. They also promote...

Acute inflammation is a rapid, short-lived physiological response to tissue injury or infection, designed to eliminate harmful agents and initiate repair. This tightly regulated process typically lasts from minutes to several days and is triggered by factors such as microbial invasion, physical trauma, or chemical injury.Recognition and Mediator ReleaseThe inflammatory response begins when resident immune cells—such as mast cells, macrophages, and dendritic cells—detect damage-associated...

Introduction
Inflammatory bowel disease, commonly known as IBD, refers to a collection of disorders that lead to persistent inflammation of the gastrointestinal tract. The two types of IBD are ulcerative colitis, which impacts the colon, and Crohn's disease, which can involve any part of the gastrointestinal segment.
Crohn's disease
Crohn's disease is a chronic, systemic inflammatory bowel disease (IBD) that predominantly affects the gastrointestinal tract. It is marked by transmural...