{{Short description|Human chronic inflammatory disease}} {{Technical|date=October 2012}} {{Infobox medical condition (new) | name = Lichen nitidus | image = Photography of lichen nitidus.jpg | caption = Photography of lichen nitidus: A) Glistening forearm papules; B) Papular lesions of lower limbs | | pronounce = | field = | synonyms = | symptoms = | complications = | onset = | duration = | types = | causes = | risks = | diagnosis = | differential = | prevention = | treatment = | medication = | prognosis = | frequency = | deaths = }} '''Lichen nitidus''' is a chronic inflammatory disease of unknown cause<ref name="Mutairi">{{cite journal |vauthors=Al-Mutairi N, Hassanein A, Nour-Eldin O, Arun J |title=Generalized lichen nitidus |journal=Pediatr Dermatol |volume=22 |issue=2 |pages=158–60 |year=2005 |pmid=15804308 |doi=10.1111/j.1525-1470.2005.22215.x |s2cid=6281902 }}</ref> characterized by 1–2&nbsp;mm, discrete and uniform, shiny, flat-topped, pale flesh-colored or reddish-brown papules<ref name="Andrews">{{cite book |author1=Berger, Timothy G. |author2=Odom, Richard B. |author3=Andrews, George E. |author4=James, William D. |title=Andrews' Diseases of the skin: clinical dermatology |publisher=W. B. Saunders |location=Philadelphia |year=2000 |pages=277–80 |isbn=0-7216-5832-6 }}</ref><ref name="Freedberg">{{cite book |author1=Fitzpatrick, Thomas B. |author2=Freedberg, Irwin M. |title=Fitzpatrick's dermatology in general medicine |publisher=McGraw-Hill, Health Professions Division |location=New York |year=1999 |pages=577–81 |isbn=0-07-912938-2 }}</ref> that may appear as hypopigmented against dark skin. Occasionally, minimal scaling is present or can be induced by rubbing the surface of the papules.<ref name="Freedberg" /> The disease usually affects children and young adults<ref name="Soroush">{{cite journal |vauthors=Soroush V, Gurevitch AW, Peng SK |title=Generalized lichen nitidus: case report and literature review |journal=Cutis |volume=64 |issue=2 |pages=135–6 |year=1999 |pmid=10467510 }}</ref> and is painless and usually nonpruritic, although protracted itching may occur in some cases.<ref name="Freedberg" /><ref name="Maeda" /> It is sometimes referred to by dermatologists as "mini lichen planus".

==Presentation== Linear arrangements of these papules is common (referred to as a Koebner phenomenon), especially on the forearms,<ref name="Andrews" /><ref name="Maeda">{{cite journal |author=Maeda M |title=A case of generalized lichen nitidus with Koebner's phenomenon |journal=J. Dermatol. |volume=21 |issue=4 |pages=273–7 |year=1994 |doi=10.1111/j.1346-8138.1994.tb01736.x |pmid=8056902 |s2cid=25028714 }}</ref> but may occasionally be grouped, though not confluent, on flexural areas.<ref name="Andrews" /> Generally, the initial lesions are localized, and remain so, to the chest, abdomen, glans penis, and flexor aspects of the upper extremities;<ref name="Do">{{cite journal |vauthors=Do MO, Kim MJ, Kim SH, Myung KB, Choi YW |title=Generalized Lichen Nitidus Successfully Treated with Narrow-band UVB Phototherapy : Two Cases Report |journal=J. Korean Med. Sci. |volume=22 |issue=1 |pages=163–6 |year=2007 |pmid=17297274 |doi= 10.3346/jkms.2007.22.1.163|url=http://jkms.org/contents/jkms.php?pubyear=2007&vol=22&fpage=163 |pmc=2693559 }} {{Dead link|date=June 2010}}</ref> however, less commonly, the disease process can (1) be strictly isolated to the palms and soles,<ref name="Thibaudeau">{{cite journal |vauthors=Thibaudeau A, Maillard H, Croué A, Belperron P, Avenel Audran M, Verret JL |title=[Palmoplantar lichen nitidus: a rare cause of palmoplantar hyperkeratosis.] |language=fr |journal=Ann Dermatol Venereol |volume=131 |issue=8–9 |pages=822–4 |year=2004 |pmid=15505553 |doi= 10.1016/S0151-9638(04)93769-6|url=http://www.masson.fr/masson/MDOI-AD-08-2004-131-8-9-0151-9638-101019-ART14|url-access=subscription }}</ref> presenting with many hyperkeratotic, yellow papules that may coalesce into plaques that fissure<ref name="Freedberg" /><ref name="Thibaudeau" /> or “...sometimes a non-specific keratoderma resembling chronic eczema,”<ref name="Thibaudeau" /> or (2) become more widespread, with papules widely distributed on the body—the extensor surfaces of the elbows, wrists, and hands, folds of the neck, submammary region in females, groin, thighs, ankles, and feet<ref name="Mutairi" /><ref name="Andrews" />—and fusing into erythematous, minimally scaled plaques, with redness that develops tints of violet, brown, and yellow.<ref name="Freedberg" /><ref name="Soroush" />

==Pathology== thumb|Histopathology of lichen nitidus: Downward extension of the rete ridges at the lateral margins of a lymphohistiocytic infiltrate, resulting in a typical "claw clutching a ball" appearance. The histology of lichen nitidus is significant for a "...localized granulomatous lymphohistiocytic infiltrate in an expanded dermal papilla with thinning of overlying epidermis and downward extension of the rete ridges at the lateral margin of the infiltrate, producing a typical 'claw clutching a ball' picture...."<ref name="Mutairi" />

==Treatment== Generally, lichen nitidus is asymptomatic and self-limited; therefore, no treatment is required. However, if persistent pruritus is present, or the appearance “...interferes with daily activities or outlook...”<ref name="Andrews" /> topical glucocorticoids may be tried. If the disease process is symptomatic, generalized and extensive, oral glucocorticoids may be indicated.<ref name="Andrews" /> Other reported treatments include PUVA, UVA/UVB phototherapy,<ref name="Do" /> astemizole,<ref name="Mutairi" /> acitretin, and etretinate.<ref name="Andrews" /> When appears with sun/humidity; air conditioning (cool dry air) reduces swelling and discomfort.

==History== {{ill|Felix Pinkus|de}} first described the condition in 1907.<ref name=Crissey2002>{{cite book |last1=Crissey |first1=John Thorne |last2=Parish |first2=Lawrence C. |last3=Holubar |first3=Karl |title=Historical Atlas of Dermatology and Dermatologists |date=2002 |publisher=CRC Press |location=New York |isbn=1-84214-100-7 |page=122 |url=https://books.google.com/books?id=7ThZDwAAQBAJ&dq=lichen+nitidus+felix+pinkus&pg=PA122 |language=en}}</ref>

== See also == * Lichen planus * List of cutaneous conditions

==References== {{Reflist}}

== External links == {{Medical resources | DiseasesDB = 34283 | ICD10 = {{ICD10|L|44|1|l|40}} | ICD9 = {{ICD9|697.1}} | ICDO = | OMIM = | MedlinePlus = | eMedicineSubj = derm | eMedicineTopic = 232 | MeshID = D017513 }} *[http://www.dermnet.com/Lichen-Nitidus Lichen Nitidus] {{Webarchive|url=https://web.archive.org/web/20110903100521/http://www.dermnet.com/Lichen-Nitidus |date=2011-09-03 }} at DermNet photo library

{{Diseases of the skin and appendages by morphology}} {{Papulosquamous disorders}}

Category:Lichenoid eruptions Category:Papulosquamous disorders