Beware! Persistent skin erythema may indicate the risk of skin lymphoma

Author: Zhang Shan, Peking Union Medical College Hospital

Reviewer: Liu Jie, Chief Physician, Peking Union Medical College Hospital

Mr. Wang, 50 years old this year, has been troubled by skin problems for many years. More than a decade ago, patches of red spots began to appear on his body, with a small amount of dandruff on the surface and obvious itching. He has sought medical treatment everywhere and was diagnosed with eczema or psoriasis. Despite trying many treatments, the red spots on his skin have not improved significantly, and some of them have become thicker.

Recently, Lao Wang found some hard nodules protruding from his skin, so he went to the hospital again. After understanding Lao Wang's condition, the attending doctor considered that this was most likely a skin lymphoma and recommended that he undergo a skin biopsy. After a comprehensive examination, Lao Wang was finally diagnosed with "mycosis fungoides".

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So what is mycosis fungoides?

Under normal circumstances, there are a certain number of lymphocytes in the skin, which are an important part of the immune system. If these cells become malignant, skin lymphoma may form. Mycosis fungoides is a type of lymphoma that originates from T lymphocytes in the skin and is a malignant tumor.

The cause of mycosis fungoides is still unclear. It is common in middle-aged and elderly people, with an incidence rate of less than one in 100,000. It is a rare skin disease. In the early stages, the disease manifests as skin erythema or plaques. As the disease progresses, the skin lesions will gradually thicken and form lumps. Lymph nodes may also swell or other organs may be affected. Because the lumps on the skin may protrude from the skin surface like mushrooms during the progressive stage, it is named "mycosis fungoides".

What symptoms should prompt suspicion of mycosis fungoides?

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The early manifestations of mycosis fungoides are very similar to those of common skin diseases such as eczema, psoriasis, and pityriasis rosea. If a person is diagnosed with the above skin diseases but there is no significant improvement after one year of standardized treatment, he or she should be alert to the possibility of mycosis fungoides.

In addition, mycosis fungoides often occurs in non-exposed areas such as the armpits, buttocks, and groin. The erythema surface usually has fine desquamation, and the erythema has the characteristic of gradual progression, which will gradually develop from the initial thin erythema to plaques or raised swellings; hair loss may also occur when involving the eyebrows or scalp. If the above symptoms occur, mycosis fungoides should also be suspected.

How is mycosis fungoides diagnosed?

Diagnosis of mycosis fungoides first requires a skin biopsy, trephine or excision of skin tissue from the lesion, and further immunohistochemical staining and gene rearrangement testing may be required based on the results of the skin pathology examination. After the diagnosis of mycosis fungoides, blood tests, lymph node ultrasound, CT or PET/CT are also required to assess the severity and determine the stage.

It should be noted that because the skin pathological examination results of early mycosis fungoides may be very similar to those of diseases such as eczema and psoriasis, multiple skin biopsies or biopsies of multiple rashes may be required to confirm the diagnosis.

How is mycosis fungoides treated? Is chemotherapy necessary?

Mycosis fungoides usually develops slowly, and it often takes more than ten years from the onset of symptoms to the development to the advanced stage. Treatment methods also vary at different stages. Early stage mycosis fungoides usually only have skin lesions, and treatment is mainly medication and phototherapy. If the effect is not good, injections of interferon, oral medications, etc. may be required. Treatments for advanced mycosis fungoides include radiotherapy, targeted drugs, chemotherapy, etc. Not all patients in the advanced stage need chemotherapy. The specific treatment plan requires multidisciplinary consultations with dermatology, hematology, radiotherapy and other departments, and comprehensive assessment of the condition before formulation.

Is mycosis fungoides life-threatening?

The prognosis of mycosis fungoides is closely related to the stage. Most patients in the early stage can resume normal life after standardized treatment, and the threat to life and health is relatively small. Excessive anxiety should be avoided. Advanced mycosis fungoides usually progresses rapidly, and the treatment effect varies greatly among patients. Therefore, early diagnosis and early treatment should be carried out as much as possible. During the treatment, a good attitude should be maintained, and active cooperation with treatment and regular follow-up visits should be made to avoid adjusting drug dosages or interrupting treatment on one's own.