Polymorphic rash on light
Polymorphic photosensitivity rash is an itchy rash caused by exposure to the sun in people who have developed sensitivity to light (photosensitivity). A rash looks like small, red bumps or slightly raised spots on the skin
Polymorphic light rash usually develops in spring and early summer, when a person's contact with the sun increases. Repeated episodes of the rash are rare as summer progresses, although the disease appears around the same season every year.
Although polymorphic rash usually resolves on its own without medical intervention, medication may be necessary in severe cases. Infrequent exposure to the sun or light therapy may prevent repeated episodes of the rash
The causes of polymorphic discharge in light are not known The rash appears in people who have developed sensitivity to components of sunlight, especially ultraviolet rays from the sun and other sources such as tanning beds, etc. Sh Such sensitivity is called photosensitivity Photosensitivity is the result of immune system activation caused by sunlight As a result, inflammation and rashes develop
Ultraviolet radiation Ultraviolet radiation is a wavelength of sunlight whose wavelength is so short that the human eye cannot see it. Ultraviolet light that hits the Earth is split into two wavelengths, UV A and UV B.
People with photosensitivity have been found to react to both types of ultraviolet radiation. Although UV B light cannot pass through glass, UV A can So some people with photosensitivity may develop a rash even with closed windows
Photosensitivity Sensitivity to sunlight decreases after repeated episodes of polymorphic discharge.
The rash usually appears as a result of the first or second exposure to the sun after a long break So, the rash usually appears in spring or early summer The rash is likely to develop even if the patient goes on vacation to sunny places in winter.
As the summer progresses, shedding episodes become rarer
After the first polymorphic discharge at light, such episodes are expected to repeat in the same season of the next year.
Some people become less sensitive to light over time and may not develop a rash at all.
The rash usually appears minutes, hours, or days after exposure to the sun The rash appears in places that are covered by clothing in the winter and exposed to the sun in the summer: the upper chest, the front of the neck, and the arms.
Characteristics of discharge:
- Dense clusters of small bumps
- Raised rough spots
- Redness
- Itching and burning sensation
- Blistering and filling (less likely)
Such a condition is more related to sunburn than to light-induced polymorphous rash
When to see your doctor
See your doctor if:
- You develop any type of rash for no apparent reason, such as a known allergy
- Many conditions, including serious illnesses, cause similar rashes on the skin Timely diagnosis and appropriate treatment are necessary
Seek emergency medical help if the rash is:
- Widely spread over the body
- Painful
- Accompanied by fever
