Pannus refers to an abnormal growth or fold of tissue that can occur in various parts of the body.
Understanding Pannus
The term “pannus” originates from the Latin word for “cloth” or “garment,” aptly describing its appearance as an abnormal layer of tissue. This tissue often features a proliferation of cells, including inflammatory cells, fibrous tissue, or fat. It typically presents as a thickened or vascularized layer, meaning it contains an increased number of blood vessels. While pannus is always an abnormal growth, its specific composition and implications vary significantly based on its location and the underlying factors contributing to its formation.
Different Forms of Pannus
Pannus can manifest in diverse ways throughout the body, each with distinct characteristics and clinical significance.
Abdominal pannus, commonly known as an “apron belly,” involves an overhanging fold of skin and fat in the lower abdominal region. This condition can range in size from a slight overhang to a more pronounced apron-like shape that drapes considerably over the pubic area.
Rheumatoid pannus is associated with autoimmune conditions such as rheumatoid arthritis (RA). In this context, pannus is an inflammatory and destructive tissue that forms in joints, specifically growing over cartilage and bone. This abnormal tissue is composed of aggressive cells that release enzymes, leading to joint damage by eroding articular cartilage and bone.
Corneal pannus appears on the cornea of the eye as a vascularized, opaque layer. The cornea is typically clear and lacks blood vessels, so the presence of these vessels extending onto its surface is a notable abnormality. This form often results from chronic inflammation, infection, or issues like contact lens overwear.
Other less common forms include thyroid pannus, which can occur in Graves’ ophthalmopathy, and diabetic pannus, sometimes referring to certain skin manifestations in severe diabetes. Pannus has also been observed over prosthetic heart valves.
Why Pannus Develops
The development of pannus is generally linked to chronic inflammation, abnormal tissue proliferation, and excessive tissue growth.
For abdominal pannus, the primary factors include excess adipose tissue and significant weight changes, such as substantial weight gain or rapid weight loss. Pregnancy can also stretch abdominal skin, leading to a pannus. Skin elasticity loss, which can occur with age, also contributes to the skin’s inability to retract.
Rheumatoid pannus arises from the chronic inflammatory processes seen in autoimmune diseases like rheumatoid arthritis. In RA, the immune system mistakenly attacks the synovium, the delicate lining of the joints. This attack causes the synovium to become inflamed and thicken, leading to the formation of pannus tissue that invades and damages joint structures.
Corneal pannus development is often related to chronic irritation, infection, or a lack of oxygen to the cornea. For example, ill-fitting contact lenses can block oxygen supply to the cornea, prompting the growth of new blood vessels in an attempt to compensate. Conditions like trachoma, chronic blepharoconjunctivitis, or chemical injuries can also contribute to its formation.
Addressing Pannus
Recognizing the symptoms, obtaining an accurate diagnosis, and initiating appropriate management are important steps in addressing pannus.
Symptoms vary depending on the type of pannus. Abdominal pannus can cause skin irritation, rashes, and hygiene difficulties due to moisture trapped in skin folds. Rheumatoid pannus leads to joint pain, swelling, stiffness, and reduced mobility, potentially causing severe pain and joint deformation. Corneal pannus can manifest as vision changes, redness, discomfort, and the visible growth of blood vessels on the cornea.
Diagnosis typically involves a physical examination for abdominal or joint-related pannus. For corneal pannus, a slit-lamp examination is used to visualize the abnormal tissue on the eye. Identifying the underlying condition driving pannus formation is often part of the diagnostic process.
Management and treatment strategies are highly dependent on the type and cause of the pannus. For abdominal pannus, conservative measures like weight management and maintaining hygiene are often recommended. In more severe cases, surgical removal through a panniculectomy may be an option. Treatment for rheumatoid pannus focuses on managing the underlying autoimmune disease with medications, such as disease-modifying anti-rheumatic drugs (DMARDs), to reduce inflammation and prevent further joint destruction.
Corneal pannus treatment involves addressing the root cause, such as antibiotics for infections, improving contact lens hygiene, or using anti-inflammatory eye drops. Severe cases of corneal pannus might require laser therapy to shut down blood vessels or, in rare instances, a corneal transplant.