Lichen Striatus With Nail Involvement: Two Case Reports

Zhen-Ru Liu, Yuan Zhou, Meng-Xi Liu, Xiao-Qing Wang, Da-Guang Wang

Department of Dermatology and Venereology, The First Affiliated Hospital with Nanjing Medical University, Nanjing, Jiangsu 210029, China.

Abstract Introduction:Lichen striatus(LS)is a benign,self-limiting,linear inflammatory skin disease that was rarely reported.Here we report two cases of nail involvement in children with LS.Case presentation: Two children was referred to our hospital with asymptomatic linear eruption and nail dystrophy.Histopathological examination revealed epidermal hyperkeratosis, infiltration of inflammatory cells 9around the adnexal region, hyperpigmentation in the rete ridges, and focal liquefactive degeneration of the basal layer.Discussion: There is no specific treatment for nail LS.Without treatment, LS can resolve spontaneously over a period of time.Topical steroid treatment can improve symptoms and shorten the duration of the disease.It is important for clinicians to distinguish LS from other linear diseases, which may lead to unnecessary treatment and surgical intervention.Conclusion:The appearance of nail and skin lesions is importance of clinical features in making the diagnosis of nail LS,and also distinguish to other linear and nail diseases.

Keywords: lichen striatus, nail, dermoscopy, histopathology

Introduction

Lichen striatus (LS) is a benign, self-limiting, linear inflammatory skin disease.The lesions of LS follow a linear distribution along Blaschko’s lines.Females are affected approximately two times more frequently than males.1This disease primarily affects children between ages of 6 months and 14 years, especially preschool children.2-3Only a few cases of nail involvement on LS have been reported.LS is not easy to be diagnosed and often needs to be differentiated from other linear skin disease.We herein report two cases of nail involvement in children with LS and provide a brief review of the literature to the readers in order to rich the knowledge.

Case reports

Case 1

A 5-year-old boy was referred to the Department of Dermatology and Venereology, The First Affiliated Hospital with Nanjing Medical University, because of an approximately 1-month history of an asymptomatic linear eruption and nail dystrophy on his left thumb(Fig.1A).His mother noticed that the eruption and nail changes had appeared simultaneously, and she reported slow growth of the nail plate.The patient had received no treatment before his visit, and had no history of hypersensitivity, trauma, or any potentially causative factors.The patient’s family history was unremarkable.Examination of his oral mucosa,hair,and genital mucosa revealed no abnormalities.The skin changes presented nonvascular, hypopigmented, nonscaly, and flat-topped(Fig.1B).The nail changes were characterized by proximal onycholysis and longitudinal ridging and splitting,and the band-like pigmentation of the nail bed was consistent with the direction of the linear eruption.Histopathological examination of serial biopsy specimen sections revealed epidermal hyperkeratosis, infiltration of inflammatory cells around the adnexal region,hyperpigmentation in the rete ridges,and focal liquefactive degeneration of the basal layer (Fig.1C).

Figure 1. Clinical presentation and histological findings of the nail involved from patient with lichen striatus.(A) The skin changes presented nonvascular,hypopigmented,nonscaly,and flat-topped.(B)Dermoscopy showed that the involved nail presented longitudinal ridging splitting and the band-like pigmentation of the nail bed was consistent with the direction of the linear eruption.(C)Histopathological examination of serial biopsy specimen sections revealed epidermal hyperkeratosis,infiltration of inflammatory cells around the adnexal region,hyperpigmentation in the rete ridges, and focal liquefactive degeneration of the basal layer (HE, ×400).

Diagnosis of LS was made based on the clinical manifestations and biopsy findings.We initially administered no treatment because the boy was young, and we considered that the lesions were likely to resolve with his growth and development.At the 1-month follow-up, the nail changes had progressed to aggravation of the longitudinal splitting and defects of the distal nail plate.Therefore, we treated the patient with topical pimecrolimus ointment.Follow-up to evaluate the treatment efficiency is ongoing.The guardian of the boy gave the agreement for case publication.

Case 2

A 10-year-old girl was referred to our department because of an approximately 1-year of an asymptomatic linear eruption and nail dystrophy on the first toe of the right foot.The nail changes appeared after the linear eruption.The patient had received no treatment before her visit,and had no history of hypersensitivity, trauma, or potentially causative factors.Her family history was unremarkable.Examination of her oral mucosa,hair,and genital mucosa revealed no abnormalities.Dermatological examination demonstrated a continuous,pink,and linear pattern along Blaschko’s lines.Dermoscopy of the lesion on the toe revealed a patchy distribution of dotted vessels on a red background;the same findings were discovered in the nail matrix.The compromised nail matrix had caused the nail plate to become thin and progress to longitudinal ridging,fissuring, and splitting.The changes in the nail plate prevented clear visualization of the nail bed lesion by dermoscopy.Because the patient declined a skin biopsy,we could not perform a histopathological examination.The diagnosis of LS was made based on the clinical manifestation and dermoscopy results.We treated the patient with topical pimecrolimus ointment.At the five-month follow-up, the destruction of the nail plate was ameliorated.The guardian of the girl gave the agreement for case publication.

Discussion

LS is typically characterized by the presence of round or polygonal,pink,red,or skin-colored flat-topped lichenoid papules that may be covered with a small amount of scales.LS albus is occasionally found, and presents with hypopigmented macules or papules, as in our first case.2Only a few cases of violaceous LS have been reported.3Typical lichenoid nail abnormalities are characterized by destruction of the nail matrix with progression to thinning,longitudinal ridging,splitting,fraying,fissuring,shedding,and onycholysis.When the eruption involves the whole nail, the nail plate may be lost.

Nail involvement in LS is unusual;only 30 cases were reported from 1972 to 2015, and the youngest patient was a 9-month-old infant.4Nail LS can be found before,after, and simultaneously with skin lesions, and can also appear in isolation.However, lesions that only occur on the nail may be difficult to distinguish from other nail diseases.

Histopathologic examination of nail LS usually reveals focal spongiosis and exocytosis in the nail epithelium as well as a focal band-like infiltrate composed of lymphocytes and histiocytes in the papillary dermis of the nail matrix.In contrast to skin LS, nail LS is characterized by compact orthokeratosis and hypergranulosis leading to abnormal nail matrix keratinization.4-5Jakhar and Kaur6observed a longitudinal erythematous band by dermoscopy.They speculated that this erythematous band was associated with the pathological process of the linear lesion in the nail matrix.

Linear lichen planus, linear psoriasis, and median nail dystrophy of Heller were considered as a differential diagnosis in our patients.It is difficult to distinguish lichen planus(LP)and LS by clinical manifestations alone.These two conditions can be differentiated using the following factors.(1)Age:LS is most commonly found in preschool children,whereas LP can occur in all age groups,and it is more common in adults.(2)Inflammatory response:The inflammatory response of LS is mild.The lesion is usually pink,and hypopigmentation develops after the inflammation subsides.In contrast,the inflammatory response of LP is severe.The lesion is dark red,and pigmentation usually develops after inflammation subsides.(3)Dermoscopicfindings:LS can show both vascular and nonvascular structure, such as the radial distribution of dotted vessels and Wickham striae.LS can show band-like erythema of the nail bed.(4)Histopathology:Histopathology of both LP and LS shows inflammatory changes.LP presents more extensive inflammatory infiltration and cell liquefaction,while the inflammatory changes in LS are characterized by focal changes and intense inflammatory infiltration around adnexal structures.(5)Nail changes:Both LP and LS can lead to nail dystrophy.LP causes nail involvement from the skin lesions at the ends of fingers or toes, whereas LS directly causes the nail involvement from the nail matrix.(6)Prognosis:LP can develop into pterygium unguis with permanent destruction in about 20% of cases.7Unlike LP,LS is a self-limiting disease and the nail changes are not permanent.The mean duration of nail changes in LS is 22.6 months.8

Linear psoriasis usually occurs in persons older than 65 years or with a family history of psoriasis.7In contrast to LS,linear psoriasis can affect the nail bed,nail matrix,or both.Histological examination of nail psoriasis demonstrates hyperkeratosis,parakeratosis,neutrophilic infiltration, hypergranulosis, psoriasiform hyperplasia, dilated capillaries, and serum exudates.

Median nail dystrophy of Heller is common in the thumbnail and presents as a midline longitudinal groove with multiple transverse ridges aligned in an inverted fir tree pattern.Unlike LS, no linear papules or plaques are presented on the periungual skin.

There is no specific treatment for nail LS.Without treatment, LS can resolve spontaneously in a period of 6 months to 2 years.When lesions involve the nail,the course tends to be prolonged by 6 months to 5 years.4-5Topical 0.1% tacrolimus ointment has been successfully applied to treat children with LS and nail involvement.It has been provento shorten the mean duration of remission compared with no treatment.5Oral cyclosporine may provide an alternative treatmentforcasesthat donot respondtotopical steroid treatment.Cyclosporine can inhibit the inflammatory response, reduce morbidity, and prevent complications.9Although a 308-nm excimer laser can be used to effectively treat the hypopigmentation caused by LS,it may not be suitable for the periungual area.The laser induces melanocyte proliferation, migration, and differentiation and is associated with a risk of melanoma development.Doctors should be aware of nail changes in children and treat the nail abnormalities if necessary.