What are self-limiting diseases?
Self-limiting diseases refer to conditions where, after the symptoms have progressed to a certain level, the body's own adjustments can control the progression of the disease and gradually lead to recovery. Generally, in the absence of severe complications, only symptomatic treatment or no treatment is required, such as in some unique viral infections and autoimmune diseases. Common self-limiting diseases include pityriasis rosea, chickenpox, viral flu, acute thyroiditis, and rotavirus gastroenteritis.
Self-limiting Disease: Cold Due to Wind-Cold Invasion
As observed by biologists, the process of a cold due to wind-cold invasion typically unfolds as follows: Initially, due to vasoconstriction of the nasal mucosa, patients may feel dryness in their noses; subsequently, capillary dilation occurs, causing the nasal mucosa to swell and glandular secretions to increase, leading to an increase in nasal discharge, which is initially watery and then becomes thicker. At this point, patients may feel nasal congestion and poor ventilation, accompanied by sneezing and runny nose; followed by fever, headache, and weakness in the limbs, with nasal discharge becoming thicker and possibly yellowish and purulent, which is mostly composed of leukocytes exuded from the blood, shed mucosal epithelial cells, and killed bacteria. After approximately seven days, the symptoms of the cold gradually subside and recovery occurs. Taking medication during a cold due to wind-cold invasion can help reduce the duration and severity of the disease.
Self-limiting Disease: Chickenpox
Chickenpox is an acute infectious disease caused by the first infection with the varicella-zoster virus. The infection rate is high, primarily affecting infants, characterized by fever and the appearance of generalized red maculopapules, vesicles, and scabs in batches. It is more prevalent in spring and winter, with high infectivity and can be transmitted through contact or droplets. The incidence rate among susceptible individuals is over 95%, with school-aged children being the most common. In clinical practice, the disease is characterized by the sequential appearance of macules, vesicles, and scars on the skin and mucosa. This disease is self-limiting, and after recovery, lifelong immunity can be acquired, although herpes zoster may occur due to recurrent infection many years later.
Self-limiting Disease: Pityriasis Rosea
When pityriasis rosea first appears, it is usually a single, large, light pink plaque with a mild scaling edge,椭圆形shaped, commonly found on the chest, abdomen, or back. It is often misdiagnosed as a fungal infection. This single, large, light pink plaque is also known as the herald patch. Over the next one to two weeks, more dark spots or plaques may appear on the body and limbs, potentially spreading to the neck but rarely affecting the face. These later-appearing plaques are similar in appearance to the herald patch but are generally smaller in size. Approximately 40% to 50% of patients may experience mild itchiness, which may become more severe in warmer environments. Some patients may also experience fatigue and other flu-like symptoms before the appearance of red rashes. Pityriasis rosea typically reaches its peak around half a month after the herald patch appears and then gradually resolves spontaneously, usually disappearing completely within about six to eight weeks. However, some patients may experience persistent rashes for longer periods, with a very few patients experiencing symptoms for several months.
