Lichen planus symptoms, common manifestations

There are many types of lichen planus, including typical, atypical, and drug-induced. Many people will scratch with their hands when they experience itching during an acute attack, which can affect the entire body. Timely drug treatment is required, and good care must be taken in daily life, with a restricted diet.

1. Typical lichen planus

The disease is more common in adults, with a high incidence age of 30 to 60 years old. It is rare in children and the elderly, and is slightly more common in women than in men. The typical skin lesions are purple or dark red, reddish-brown pinhead to lentil-shaped polygonal flat papules with clear edges and a thin layer of adhesive scales with a waxy luster (Figures 1, 2). Sometimes a slight concave center or tiny keratin plugs can be seen. The surface of the papules has grayish-white spots and interlaced reticular stripes, called Wickham lines, which appear clearer after smearing with liquid oils. The lesions are red spots at first, and purple papules form after a few weeks. Sometimes they can develop and spread rapidly in a short period of time. The lesions can merge with each other to appear as lichen-like patches of varying sizes and shapes, with scattered rashes around them.

In the acute phase, linear isomorphic reactions appear after scratching. The rash can occur anywhere on the body, often symmetrically, and is more common on the flexor side of the limbs, medial thigh, popliteal fossa, buttocks and waist. It also often occurs on the neck. The patient is pruritus with varying degrees of itching, even severe itching. A few have no conscious symptoms.

2. Drug-induced lichen planus

Drug-induced lichen planus occurs after injection, contact and inhalation of certain chemicals. The time when skin lesions appear is from a few months to 1 year after medication, or longer, which is related to the dosage, individual sensitivity, exposure and usage of the drug. The time for the lesions to disappear varies, but it is usually 3 to 4 months. The lichenoid rash caused by gold preparations may disappear 2 years after stopping the drug. The rash can be a typical or atypical manifestation of lichen planus, which is localized or widespread eczematous papules and plaques, irregular polygons, with post-inflammatory pigmentation, hair loss and loss of typical Wickham lines. It often occurs on the trunk and limbs, and the rash is mostly symmetrical, with less mucosal involvement. The course of this disease is chronic, lasting for several months to several years. Most of them disappear on their own within 1 to 2 years. Oral lesions can persist for more than 20 years, leaving temporary pigmentation, hypopigmentation or atrophic scars after healing.

3. Atypical lichen planus The clinical manifestations of lichen planus vary . There are many types according to the onset, rash morphology and different arrangements. The most common ones are listed below.

(1) Lichen planus

liuearis): The lesions are arranged in lines of varying lengths, often distributed along nerve segments or vascular pathways, and sometimes occur at sites of trauma or scratches, forming a homomorphic reaction. They are often found on one side of the limbs, especially on the posterior side of the lower limbs, and sometimes can extend to the entire limb (Figure 5). They need to be differentiated from linear lichen vulgaris, linear psoriasis, and linear nevus.

(2) Lichen planus

annularis: It accounts for about 10% of lichen planus. Most rashes are arranged in rings, or the rashes spread to the periphery, with slightly raised edges and slightly depressed or atrophic centers. When there are many lesions, they may be ring-shaped. They are common on the penis, glans penis (Figure 6), labia majora or oral mucosa. Lesions occurring on the trunk and limbs may reach 2 to 3 cm in diameter, with raised edges and pigmentation, and are easily misdiagnosed as annular granuloma.