Pigmented lichen planus

Many kinds of diseases can be divided into different disease types according to different disease symptoms. Lichen planus has many symptoms, so there are many types of lichen planus. Pigmented lichen planus is a type of disease whose medical cause is still not very clear, and the treatment of pigmented lichen planus is also very complicated. So what should a person do after developing lichen planus pigmentosa?

Pigmented lichen planus is an extremely rare subtype of lichen planus. The cause of the disease is still unclear. It is currently believed that it may be related to infection, autoimmunity, genetics, mental health, environmental pollution, and oral medications (such as drugs containing gold and bismuth). The diagnosis of pigmented lichen planus is based on the characteristics of the rash, its chronic course, and characteristic histopathological changes.

The pathological changes of pigmented lichen planus are edema and degeneration of basal cells, but no compensatory proliferation of keratinocytes. Therefore, the epidermis becomes thinner without acanthosis, the pigment of the basal layer of the epidermis increases significantly, and obvious pigment incontinence is seen. Dense band-like infiltration dominated by lymphocytes is not seen in the dermis. Red Civatte bodies and melanophages are present in the papillary dermis.

Clinically, pigmented lichen planus needs to be differentiated from pigmented pityriasis rosea, fixed drug eruption, and erythema dyschromicum perstans.

Pigmented pityriasis rosea is common in young people after puberty. The affected areas are the trunk and proximal limbs where pigmentation spots appear, distributed consistently with the skin texture. Initially, they appear as rose-colored erythema, which turns into light brown in about ten days and eventually dark brown. They do not disappear for many years and have a relatively long course.

Fixed drug rash, as the name suggests, refers to damage to the skin or mucous membranes caused by any drug entering the body through any route. It is an adverse drug reaction, a mild drug rash, and a more common type. The shape of fixed drug eruption is quite special and it is easy to identify. It is characterized by local itching first, followed by round or oval erythema, which is bright red or purple-red and edematous. The more frequent the drug eruption, the darker the pigmentation, and pigmentation may occur after recovery.

The clinical manifestations of erythema persistent pigmentosa are varied. The typical rash is initially erythema, which gradually expands into gray-brown or gray-green patches. The lesions may be limited to the face, neck and other parts, or may occur throughout the body. Due to the coexistence of lesions at different stages, dark red, gray-brown and gray-black patches may be seen at the same time, and hypopigmented spots may also be seen.