A case report of lichen nitidus and its dermoscopic features

Lichen nitidus is clinically characterized by the presence of multiple discrete papules that are tiny, shiny, and of varied colours. They most commonly occur on the neck, trunk, forearms, abdomen and the genitalia, however cases with generalized skin involvement have also been reported. Skin lesions are usually not accompanied by any additional symptoms with a sporadic exception of mild pruritus [1]. The differential diagnosis of lichen nitidus includes follicular eczema [2], frictional lichenoid dermatitis, lichen scrofulosorum, pinpoint polymorphous light eruption, and papular urticaria [3].
One example is a 45-year-old man with a 1.5-year history of recurrent lesions situated on the upper part of his back. The first symptoms appeared in the interscapular area with a tendency to widen the area to cover the entire surface of the back. The physical examination revealed numerous shiny papules of the colour of the surrounding skin, 1–2 mm in diameter (Figure 1). There were no pathological changes on the mucous membranes or on the nails.
The treatment so far has involved topical retinoids, glucocorticoids, and antihistamines; there was a noticeable improvement, but the symptoms worsened after drug discontinuation. Diabetes was diagnosed during hospitalization, and no other pathology was found in the results of laboratory tests. The patient reported that he smoked about 30 cigarettes a day. The dermoscopy performed (DermLite DL4 3Gen, 10-fold magnification, polarized) revealed the presence of white oval but irregular, structureless areas with a peripheral halo with pinkish pigmentation (Figure 2 A).
Histopathological evaluation of the 3 mm punch biopsy taken from the lesion showed a skin fragment with a single hair follicle on the left side. In the central part, there is a well-delineated mononuclear cell infiltration closely adjoining the epidermis. The epidermis at this height is thinned and covered with a compact layer of keratin and focally parakeratin. This contrasts with the normal basket keratin layer of the remaining epidermis. Increased rete peg laterally adjoins the infiltration on the right side. Sparse lymphocytic infiltrations are present around the vessels of the superficial plexus.
Although diagnosis is mostly clinical, some of the cases require histopathological confirmation for this entity [3].
The histopathologic findings of lichen nitidus are characteristic, consisting of well-circumscribed infiltrate...


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