Abstract: 13 year-old boy with a few years history of lichen nitidus
HPI: This is a 13 year-old Hispanic boy who presented for treatment of warts. During the exam, multiple small white shiny dots were noticed. The patient has been aware of these asymptomatic lesions for the past few years. He had been given triamcinolone 0.1% ointment bid, but forgot to apply it because it did not bother him.
O/E: There are multiple pinhead-sized 1 mm white shiny flat-topped papules in an oval shape on the right knee.
The dermoscopic image taken with the Canfield Dermatoscope with iPhone attachment
While there are many dermoscopic studies on the skin cancers, there is a growing interest of dermoscopic features on other skin diseases such as inflammatory diseases, connective tissue disorders, or even psychogenic related skin diseases. Lichen nitidus is easily recognized clinically with experienced eyes. With my own interest in dermoscopy, I report an interesting dermoscopic finding of lichen nitidus. There are 1-2 mm multiple small white circles which represent subepidermal infiltrate of lymphocytes, histiocytes, and multinucleated giant cells in the dermal papillae.
Lichen nitidus was first described by Pinkus in 1907. Lichen nitidus, which means shiny papules, is a relatively uncommon, asymptomatic, chronic eruption, consisting of minute sharply demarcated skin-colored papules. It has a predilection for males (4:1) and the mean age of onset was 7 yrs for males and 13 yrs for females. Typically, patients present for assessment with an asymptomatic or mildly pruritic eruption. The eruption may be localized to one or more areas or generalized in distribution. The pathogenesis of lichen nitidus is unknown. It was originally believed to be a form of tuberculid and more recently considered to be a variant of lichen planus. Histologially, lichen nitidus is characterized by a circumscribed collection of inflammatory cells in the papillary dermis that abuts the overlying epidermis. The inflammatory infiltrate consists of lymphocytes, histiocytes, and multinucleated giant cells. DIF negative. Most cases require no treatment due to the asymptomatic nature of the eruption and tendency for spontaneous resolution. For symptomatic cases, moderately potent or potent topical steroid therapy may help. There are a number of anecdotal reports of improvement or clearance with narrow band UVB phototherapy, extensive sunlight exposure, oral astemizole, oral cetirizine-levamisol combination, topical dinitrochlorobenzene, itraconazole and oral cyclosporin. Oral retinoids have been used successfully in the treatment of palmoplantar lichen nitidus.
L. Nitidus eMedicine (free open access)
Comment: By DJ Elpern. This is the first report of the dermatoscopic appearance of L. nitidus. Yoon Cohen deserves credit for this observation.