Indian Journal of Oral Health and Research

CASE REPORT
Year
: 2019  |  Volume : 5  |  Issue : 1  |  Page : 32--35

Lichen planus pigmentosus: A report of two cases


Hena Shaw1, Aravinda Konidena1, Abhilash Malhotra1, Nishant Kumar2,  
1 Department of Oral Medicine and Radiology, Swami Devi Dyal Hospital and Dental College, Barwala, Haryana, India
2 Department of Oral Pathology and Microbiology, Career Post Graduate Institute of Dental Sciences, Lucknow, Uttar Pradesh, India

Correspondence Address:
Dr. Aravinda Konidena
Department of Oral Medicine and Radiology, Swami Devi Dyal Hospital and Dental College, Barwala, Haryana
India

Abstract

Lichen planus pigmentosus is a condition characterized by persistent and asymptomatic slaty-gray pigmentation, predominantly in the face. Two patients, aged 11-year-old female and 35-year-old male, reported to the Department of Oral Medicine and Radiology with burning sensation on taking spicy foods. On examination, only extensive symmetric brownish-black pigmentation of the buccal mucosa was observed bilaterally. The workup and management of these cases are presented along with the relevant review of literature.



How to cite this article:
Shaw H, Konidena A, Malhotra A, Kumar N. Lichen planus pigmentosus: A report of two cases.Indian J Oral Health Res 2019;5:32-35


How to cite this URL:
Shaw H, Konidena A, Malhotra A, Kumar N. Lichen planus pigmentosus: A report of two cases. Indian J Oral Health Res [serial online] 2019 [cited 2019 Dec 11 ];5:32-35
Available from: http://www.ijohr.org/text.asp?2019/5/1/32/261150


Full Text



 Introduction



Lichen planus pigmentosus (LPP) is a condition characterized by persistent, asymptomatic slaty-gray pigmentation.[1] It was first described by Bhutani in 1974.[2] This disease of unknown etiology runs an insidious, prolonged course and is characterized by pruritus, macules of dark-brown color distributed principally in the sun-exposed areas of the body, especially in dark-complexioned individuals. The disease may involve the mucosa but spares the scalp and nails.[3] We recently encountered two patients who presented with burning sensation and unusual brownish-black pigmentation of the buccal mucosa. The clinical details along with relevant literature are being presented here due to their atypical appearance.

 Case Reports



Case report 1

An 11-year-old female patient presented to our department with a chief complaint of burning sensation of the inner side of cheeks on intake of spicy food for 3–4 months. She reported that burning sensation relieved by itself after food intake. She approached several dental practitioners and used medication but had no relief. On enquiry, she reported pain and itching in both the eyes about 5 months back, followed by the onset of burning sensation in the mouth. There was no history of the use of medication for any systemic illness. Her medical history and general physical examination were unremarkable. No lesions were noted on the skin of limbs or trunk. Regional lymph nodes were not palpable. Intraoral examination revealed a symmetrical diffuse macular brownish-black pigmentation seen bilaterally on the buccal mucosa, 1 cm away from commissure of lip to the retromolar region. Superoinferiorly, the lesion extended from upper vestibular depth to the lower vestibule sparing about 1 cm zone along the occlusal plane is shown in [Figure 1] and [Figure 2]. The pigmentation showed wavy line appearance. Surrounding mucosa appeared to be normal. On palpation, it had a smooth texture and was soft in consistency. Based on the history and clinical examination, the provisional diagnosis of postinflammatory pigmentation of oral LP was considered. Oral pigmentation due to deficiency of Vitamin B12, LPP, was considered under differential diagnosis. Her hematological profile was within normal limits. After obtaining consent from her father, an incisional biopsy from the right buccal mucosa was taken. Histopathological examination of the section studied under hematoxylin and eosin staining revealed irregular hyperplasia with spongiosis of the epithelium. Sawtooth-shaped rete pegs were seen with lymphomononuclear cell infiltrate with occasional melanin incontinence. Exocytosis was focally evident. These histopathological findings were suggestive of LPP, and a final diagnosis of LPP was made.{Figure 1}{Figure 2}

The patient's guardian was counseled regarding the disease nature, and the prognosis was explained. She was advised topical application of Kenacort ointment (0.1% triamcinolone acetonide) thrice a day and lycopene capsule once daily for 1 week. The patient reported was free of symptoms within 20 days with significant reduction in the intensity of pigmentation [Figure 3] and [Figure 4].{Figure 3}{Figure 4}

Case report 2

A 35-year-old male patient presented to our department with a chief complaint of burning sensation in the oral cavity on intake of spicy food for 1 year. He did not report any regular use of any medication. His medical history and general physical examination were unremarkable. This patient also did not report tobacco or alcohol abuse. No lesions were noted on the body. Intraoral examination revealed a symmetrical diffuse macular grayish-black pigmentation seen bilaterally on the buccal mucosa, from commissure of the lip till midbuccal mucosa region along the occlusal plane [Figure 5] and [Figure 6]. Surrounding mucosa appeared to be normal without any evidence of striae. On palpation, it had a smooth texture and was soft in consistency. Based on the history and clinical examination, the provisional diagnosis of postinflammatory pigmentation of oral LP was considered. LPP was considered under differential diagnosis. His hematological profile was within normal limits. After obtaining written informed consent, an incisional biopsy from the right buccal mucosa was taken. Histopathological examination revealed hyperkeratosis with thickening of granular cell layer. The basement membrane was intact, with sawtooth-shaped rete pegs, dense subepithelial band of chronic inflammatory infiltrate confined to lamina propria with melanin incontinence [Figure 7]. These histopathological findings were suggestive of LPP, and a final diagnosis of LPP was made.{Figure 5}{Figure 6}{Figure 7}

He was advised topical application of Kenacort ointment thrice a day and lycopene capsule once daily for 1 week. The patient reported was free of symptoms within a week.

 Discussion



LPP is a chronic pigmentary disorder of unknown etiology. Cases from India, Japan, Korea, the Middle East, and Latin America have been reported.[3] As in our case, etiology is essentially unknown, despite a number of agents being reported as predisposing factors. The occurrence in sun-exposed areas in many patients has led to the assumption that sunlight may be the principal etiological agent. Other postulated agents are hepatitis C virus, mustard oil (contains the potential photosensitizer allyl thiocyanate, amla oil where photosensitivity may be caused by fragrances), and cosmetic agents such as kumkum and hair dyes. Abnormalities in the T-lymphocyte functions have also been implicated.[3] Our patients denied the use of these external agents and could not be investigated for hepatitis C.

LPP is most common over the sun-exposed areas such as the face, neck, and flexural folds, including the axillary, inguinal, and submammary regions. Rarely, involvement can be generalized. Palms, soles, and nails are not affected, and involvement of the oral mucosa is infrequent. The patient may continue to develop new lesions, whereas old ones enlarge with gradual extension in size and deepening in color. Although lesions are generally asymptomatic, mild pruritus and burning sensation are reported in about one-third of the patients.[4] Our patients were symptomatic and presented only with lesions of the oral mucosa.

Kanwar et al.[5] reported that LPP usually affects adults with a female predilection but is rare in children. On contrast, our patients were young prepubertal female and a 35-year-old male. According to Bhutani,[2] LPP, an uncommon variant of LP, is characterized by diffuse, mottled, reticulated, or perifollicular hyperpigmented, dark-brown macules. The initial lesions are small, brown, oval macules with diffuse borders. The patches are usually symmetrical in distribution as seen in our case but may be found in a segmental, zosteriform, or blaschkoid pattern.[3] A number of other variants such as localized LPP (on thigh), segmental LPP, linear LPP: LPP in zosteriform distribution; LPP along the lines of Blaschko; and LPP of oral mucosa have been reported. LPP differs clinically from classical LP by exhibiting dark-brown macules and/or papules and a longer clinical course without pruritus, scalp, nail, or mucosal involvement.[3] Our patients also presented with oral pigmentation alone which was symptomatic.

Erythema dyschromicum perstans is considered as the principal differential diagnosis of LPP. Other differentials are fixed drug eruption, macular amyloidosis, urticaria pigmentosa, tar melanosis, frictional melanosis, berloque dermatitis, pigmented cosmetic dermatitis (Riehl's melanosis), postinflammatory hyperpigmentation, and idiopathic eruptive macular pigmentation and hyperpigmentation due to drugs and heavy metals.[3]

The predominant histopathological changes noted include a perivascular lymphohistiocytic infiltrate in the dermis, the presence of melanophages or with melanin incontinence. LPP thus follows the typical changes seen in LP but with thinning of the epidermis. A band-like infiltrate of lymphocytes is usually found at the dermo-epidermal junction. Other salient features include hyperkeratosis, wedge-shaped hypergranulosis, acanthosis with sawtoothed rete ridges, and vacuolar degeneration of the basal layer. Civatte bodies (colloid or cytoid bodies) may be present at the dermo-epidermal junction and in the papillary dermis. The presence of these findings in skin biopsies suggests that LPP probably represents a lichenoid reaction to an unknown agent or stimulus and that a histopathological similarity exists between LPP and LP.[4] Our patients also presented with some of the typical LP features as described earlier with melanin incontinence.

According to the literature, LPP has no effective treatment. Vitamin A was recommended by Bhutani for the treatment of LPP.[2] Other workers have claimed that topical and systemic corticosteroids clear the lesions rapidly.[3] Our patients responded very well to topical steroids and antioxidants. Al-Mutairi and El-Khalawany[6] found tacrolimus ointment (0.1%) to be effective in 53.8% of patients. A few cases have responded well to pigment laser. Sehgal et al.[7] suggested a combination of oral diamino-diphenyl-sulfone (dapsone) along with oral immunomodulator, topical tacrolimus along with photoprotection for the treatment of LPP.[3] The treatment of facial LPP includes the removal of aggravating factors, vigorous photoprotection, and some form of active pigment reduction. Topical agents include hydroquinone, which is the most commonly used agent, often in combination with retinoic acid, corticosteroids, azelaic acid, kojic acid, and glycolic acid.[4] However, since our patients responded to topical steroids, no other treatment modalities were required.

 Conclusion



Oral mucosal pigmentation has a diverse etiology and varied presentation. LPP is a distinct entity very similar to OLP clinically and histologically but with basilar hyperpigmentation and melanin incontinence. A clinician should consider LPP as a possibility in cases of unexplained and unusual mucosal pigmentation, since early recognition facilitates prompt management of the condition, thus relieving the patient's discomfort.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form, the patients' father and the second patient have given their consent for their images and other clinical information to be reported in the journal. The patients' father and the second patient understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

References

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