Connective Tissue Disease

Summary:

Connective Tissue Disease encompasses various conditions affecting connective tissues. Investigations can include tests to diagnose vasculitis, a condition causing blood vessel inflammation. Cutaneous vasculitis has multiple possible causes and may present as polyarteritis nodosa (PAN) or Henoch-Schönlein purpura (IgA vasculitis). Proper management is vital for patients with cutaneous vasculitis.

Other connective tissue diseases include chilblains (perniosis), Raynaud’s phenomenon, systemic sclerosis (SSc), CREST syndrome, lichen planus (LP), lupus erythematosus (LE), and dermatomyositis. Lupus erythematosus has several clinical variants, and mixed connective tissue disease (MCTD) is another related condition. Understanding these various connective tissue diseases, their presentation, and appropriate management is essential for effective patient care.

Excerpt:

Connective Tissue Disease, Vasculitis, and Related Disorders (Dermatology)

Introduction
The skin is a dynamic interface of trafficking immune cells that may remain localised and respond to nearby stimuli or migrate through the skin in response to more distant triggers. The skin has been called ‘the immunological battleground of the body’, and immune cells involved in inflammatory reactions may be part of a local immune reaction or migrate to the skin as a result of antigenic stimuli at distant sites. Malfunction of the sophisticated human immune system may result in the body attacking its own tissues, that is, failure to distinguish ‘self’ from ‘non‐self’. These autoimmune responses may develop against tissue in a specific organ, such as the thyroid gland, or to tissues within and between organs resulting in connective tissue diseases.

Connective tissue disease
Connective tissue disease can be difficult to define but encompasses disorders that involve tissues connecting and surrounding organs.

Connective tissues include the extracellular matrix and support proteins such as collagen and elastin. Acquired disorders of connective tissue are thought to have an autoimmune basis, many of which have distinctive clinical features and patterns in laboratory investigations. However, at times classification may not be easy. What triggers dysregulation of the immune system is usually unknown; however, some recognised factors include sunlight, infections, and medication. Patients may have an underlying hereditary susceptibility to developing autoimmune diseases, marked by specific HLA (human lymphocyte antigen) types in some cases.