Joint pain and eczema: is there a connection?

Joint pain affects a large number of individuals. It is estimated that approximately a quarter of the French population suffers from arthritis. Athletes, people engaged in strenuous activity, and the elderly are most exposed to this issue. Generally, the areas affected by loss of muscle flexibility are the back, hips, elbows, knees, and hand joints. In general, joint pain manifests during movements that stress a joint. They are a result of the gradual degradation of the cartilage that covers the bone ends of the joints, which leads to pain and stiffness.

At a molecular level, osteoarthritis is characterised by the release of interleukin-1 (IL-1) into the cartilage. This stimulates the production of free radicals, which are involved in theapoptosis of chondrocytes, the resident cells of the cartilage. Interleukin-1 is also responsible for the release of pro-inflammatory prostaglandins, which cause inflammation in the area. Finally, high levels of NGF (nerve growth factor) are observed in patients with osteoarthritis. This growth factor binds to cellular receptors and sensitises the nociceptive terminals.

Sometimes, it is assumed that certain joint pains are linked to eczema and vice versa. However, although both these conditions are caused by inflammation, there is no connection between them. Indeed, eczema is the result of inflammation in the skin, while joint pain arises from inflammation of the joints. Nevertheless, it is entirely possible for a person to suffer from both eczema and joint pain, as these two conditions are not mutually exclusive.

The confusion and supposed link between eczema and arthritis actually stems from a disease called psoriatic arthritis, a specific form of psoriasis that causes joint pain. By analogy, it is sometimes thought that there is also a form of eczema that affects the joints. However, although both eczema and psoriasis are inflammatory skin diseases, they do not cause the same symptoms and should not be confused.