Generalized Lichen Nitidus in a Middle-Aged Adult

Lichen nitidus (LN) is a benign micropapular eruption of unknown etiology that often follows an unpredictable course. LN typically affects children and young adults and presents with asymptomatic, discrete, uniform, skin colored, pin-point sized papules. These papules are commonly found on the chest, abdomen, flexor surfaces of the upper extremities, dorsal hands, and anogenital region. Focal presentation is more common, while generalized distribution of LN is rarer and seen almost exclusively in pediatric patients. Patients are typically asymptomatic, though pruritus can occur. An uncommon case of generalized LN is reported in a middle-aged adult emphasizing an approach to diagnosis and treatment. In the majority of affected patients, LN is associated with spontaneous resolution after a few months to years, but clinical course of the generalized form is unpredictable. Generalized cases are infrequently noted, with the majority of reported cases affecting children. Due to the rarity of presentation of generalized LN in adults, skin biopsies were essential in confirming the diagnosis. Biopsies characteristically show a lymphocytic infiltrate with downward extension of lateral rete ridges forming a typical “ball-and-claw” formation.

Lichen nitidus (LN) is a benign micropapular eruption of unknown etiology that often follows an unpredictable course. LN typically affects children and young adults and presents with asymptomatic, discrete, uniform, skin colored, pin-point sized papules. 1 These papules are commonly found on the chest, abdomen, flexor surfaces of the upper extremities, dorsal hands, and anogenital region. 1 Focal presentation is more common, while generalized distribution of LN is rarer and seen almost exclusively in pediatric patients. 2 Patients are typically asymptomatic, though pruritus can occur. 1 An uncommon case of generalized LN is reported in a middle-aged adult emphasizing an approach to diagnosis and treatment.
In the majority of affected patients, LN is associated with spontaneous resolution after a few months to years, but clinical course of the generalized form is unpredictable. 3 Generalized cases are infrequently noted, with the majority of reported cases affecting children. 4 Due to the rarity of presentation of generalized LN in adults, skin biopsies were essential in confirming the diagnosis. Biopsies characteristically show a lymphocytic infiltrate with downward extension of lateral rete ridges forming a typical "ball-and-claw" formation. 1 It is not necessary to treat localized presentations of lichen nitidus as they typically resolve over a month to a year. 4 Patient and provider chose to treat this diffuse, worsening generalized. Treatment

INTRODUCTION
Lichen nitidus (LN) is a benign micropapular eruption of unknown etiology that often follows an unpredictable course. LN typically affects children and young adults and presents with asymptomatic, discrete, uniform, skin colored, pin-point sized papules. 1 These papules are commonly found on the chest, abdomen, flexor surfaces of the upper extremities, dorsal hand, and anogenital region. 1 Focal presentation is more common while generalized distribution of LN is rarer and seen more exclusively in pediatric patients. 2 Although patients are typically asymptomatic, pruritus is sometimes a noted symptom. 1 We report the diagnosis and treatment of an uncommon case of generalized LN in a middle-aged adult.

ABSTRACT
can also provide relief of pruritus. Treatment options include oral antihistamines, systemic or topical steroids, acitretin, psoralen ultraviolet A (PUVA), narrow-band ultraviolet B (NB-UVB) and dinitrochlorobenzene. 2,3 Although it is difficult to evaluate the effectiveness of treatment in a rare disease with a propensity to spontaneously resolve, phototherapy may be the most beneficial treatment for generalized LN with the least potential for side effects. 4 Broadband UVB and PUVA have greater carcinogenic potential. NB-UVB is, therefore, preferred. It is thought to deplete Langerhans cells and promote the production of anti-inflammatory factors. 3 NB-UVB was elected for this patient but her insurance would not cover the treatment. The patient was lost to follow up, but she stated in follow up emails that she had some resolution of LN.
The unusual features of older patient age, generalized distribution, and marked pruritus in the setting of comorbid primary biliary cirrhosis makes this case of LN particularly unique. It is important for dermatologists to recognize the variable presentations of uncommon cutaneous diseases like generalized LN and the need for biopsy in establishing a definitive diagnosis.