Sweet’s syndrome, also known as acute febrile neutrophilic dermatosis, is a condition that causes sudden fever and painful, red skin lesions. Understanding what causes Sweet’s syndrome involves looking at a complex interplay of factors related to the immune system, infections, medications, and sometimes underlying diseases.
At its core, Sweet’s syndrome is driven by an abnormal immune response. The immune system, which normally protects the body from infections and injuries, mistakenly triggers inflammation in the skin and sometimes other organs. This inflammation is mainly due to an overactive group of white blood cells called neutrophils. Neutrophils are usually the first responders to infection or injury, but in Sweet’s syndrome, they accumulate excessively in the skin, causing the characteristic painful, red bumps or plaques.
One of the main triggers for this immune overreaction is infection. Various bacterial, viral, or fungal infections can set off Sweet’s syndrome. The body’s immune system reacts strongly to these infections, and in some people, this response becomes exaggerated, leading to the skin symptoms. For example, respiratory infections or gastrointestinal infections have been reported to precede the onset of Sweet’s syndrome in some cases.
Another important cause is the association with certain medications. Some drugs can provoke Sweet’s syndrome by altering immune function or directly stimulating neutrophils. Medications such as antibiotics, certain cancer chemotherapy drugs, and others have been linked to the development of this condition. When the drug is stopped, the symptoms often improve, which supports the idea that medication can be a direct cause.
Sweet’s syndrome is also frequently connected to underlying systemic diseases, especially cancers and autoimmune disorders. Blood cancers like leukemia and lymphoma are among the most common diseases associated with Sweet’s syndrome. In these cases, the abnormal immune activity is thought to be related to the cancer itself or the body’s response to it. Autoimmune diseases, where the immune system attacks the body’s own tissues, can also trigger Sweet’s syndrome by creating a chronic state of immune activation.
Hormonal factors may play a role as well, given that Sweet’s syndrome is more common in women, particularly during their childbearing years. This suggests that hormones like estrogen might influence the immune system in a way that predisposes some individuals to develop the syndrome.
Genetic predisposition is another area under consideration. While Sweet’s syndrome is not directly inherited, some people may have genetic variations that make their immune systems more likely to overreact to triggers like infections or medications.
In summary, Sweet’s syndrome arises from an abnormal immune response involving neutrophils, triggered by infections, medications, cancers, autoimmune diseases, and possibly hormonal and genetic factors. The exact cause in any individual can be difficult to pinpoint because it often involves multiple overlapping influences that disrupt normal immune regulation.
