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Indian Journal of Dermatology, Venereology and Leprology, Vol. 71, No. 3, May-June, 2005, pp. 166-169 Studies Lichen amyloidosus: A study of clinical, histopathologic and immunofluorescence findings in 30 cases Salim T., Shenoi S.D., Balachandran C., Mehta Vandana Rai Department of Skin and STD, Kasturba Medical College, Manipal Code Number: dv05054 ABSTRACT BACKGROUND: Lichen amyloidosus (LA) is a primary localized cutaneous amyloidosis characterized clinically by discrete hyperkeratotic hyperpigmented papules and histologically by deposition of amyloid material in previously normal skin without any evidence of visceral involvement.AIMS AND OBJECTIVES: The aim of this work was to study the etiology, clinical features, histopathology and direct immunofluorescence findings in LA. METHODS: A prospective study of 30 patients with clinical, histological and immunofluorescence findings suggestive of LA was undertaken. After a detailed history and clinical examination, two punch biopsies for histopathology and immunofluorescence were taken. RESULTS: Of the 30 patients, 19 (63.3%) were males and 11 (36.7%) were females with duration of LA ranging from 6-20 months. Pruritus was the presenting symptom in 27 (90%) patients. Shin was involved in 26 (86.7%) followed by arms in three (10%) and back in one (3.3%). Seventeen patients (56%) had used scrubs for more than 2 years. Histopathology, direct immunofluorescence and Congo red staining detected amyloid in all cases. CONCLUSIONS: LA commonly presents over the shins as pruritic discrete hyperpigmented papules. Familial predisposition and friction may have a pathogenic role. Histopathological examination is very useful in the detection of amyloid which may be supplemented with direct immunofluorescence and Congo red staining. Keywords: Lichen amyloidosus, Direct immunofluorescence, Congo red INTRODUCTION Lichen amyloidosus (LA) is a form of primary localized cutaneous amyloidosis in which amyloid is deposited in previously normal skin without any evidence of visceral involvement.[1] Its etiology remains undetermined although it has a genetic predisposition. Chronic irritation to skin may precipitate LA. Clinically, the lesions consist of pruritic small discrete hyperkeratotic hyperpigmented papules, usually on the extensor surface of the lower limbs. On histopathological examination, amyloid deposits are restricted to the papillary dermis and direct immunofluorescence shows the presence of IgM, C3 and IgA.The aim of this work was to study the etiology, clinical features, and histopathological and direct immunofluorescence findings in LA. METHODS We undertook a prospective study of 30 patients who presented to the dermatology outpatient department with clinical features suggestive of LA (pruritic, hyperpigmented, waxy and hyperkeratotic papules in rippled pattern) and characteristic histopathological (on staining with hematoxylin and eosin or Congo red) and immunofluorescence findings (IgM, C3, IgA deposits throughout the BMZ). In all patients, a detailed history was taken and a general, cutaneous and systemic examination was carried out. After informed consent, two punch biopsies of 4 mm were performed for histopathological examination and direct immunofluorescence.RESULTS Of the 30 patients, 19 (63.3%) were males and 11 (36.7%) females with a mean age of 43.13 years. The duration of LA ranged from six to 20 months. The presenting symptom was pruritus in 27 patients (90%), with aggravation during winter in 21 (70%) and during summer in eight (26.7%). Three patients (10%) were asymptomatic.The shin was the initial site of involvement in 26 patients (86.7%), the arms in three (10%), and the back in one (3.3%). Seventeen patients (56.7%) had used scrubs for bathing for more than 2 years; 11 had used a nylon scrubber and five had used coconut fiber. A family history of LA was present in six patients (20%). All 30 patients presented with discrete hyperpigmented hyperkeratotic papules [Figure - 1]. Plaques were seen in 18 patients (60%) and biphasic amyloidosis (both macular and lichen amyloidosus) in eight. Fifteen patients (50%) had dry skin. Diabetes was an associated finding in five (16.7%) patients [Table - 1]. Histopathological examination was performed after staining with hematoxylin and eosin and Congo red dyes. Epidermal findings included hyperkeratosis in 30 (100%), acanthosis in 27 (90%), papillomatosis in 10 (33.3%), hypergranulosis in five (16.7%) and elongation of rete ridges in four (13.3%). Amyloid deposits were detected in 28 out of 30 patients as uniformly stained pink globules occupying the dermal papilla. In three patients (30%), amyloid deposits were visualized as perifollicular deposits [Figure - 2]. Twenty-one patients (70%) showed lymphocytic infiltrate in the upper dermis. Amyloid deposits were visualized using Congo red in all 30 (100%) patients. On direct immunofluorescence, biopsies from all patients showed fluorescence with IgM, C3, IgA throughout the basement membrane zone along with papillary deposits in 6 (20%), with the intensity of fluorescence being strong for IgM in most of the cases [Figure - 3]. DISCUSSION The term "amyloid" (starch-like) was coined in 1854 by Virchow who was convinced by its resemblance to starch or cellulose. Rokinstansky gave the first description of amyloidosis in 1842.[1] Chemically, there are more than 16 types of amyloid. The characteristic physicochemical properties of amyloid are congophilia and green birefringence under polarized light, fibrillar ultrastructure and cross beta pattern on X-ray diffraction. Special stains for amyloid include Congo red, PAS, Van Gieson, triphenyl methane dye and Thioflavin T. Cotton dyes like pagoda red, RIT scarlet no 5 and RIT cardinal red no 9, stain amyloid better and are long lasting.Cutaneous amyloidosis can be of papular or lichenoid, macular, and nodular or tumefactive types. A bullous variant of LA has also been identified; it is characterized by vesicles and bullae and with amyloid deposits in the papillary dermis associated with an intraepidermal or subepidermal blister.[2] Macular and papular forms may coexist in the same patient; this is known as biphasic amyloidosis. Apart from these, poikilodermic,[3] vitiliginous and anosacral variants of LA have been identified. LA is the commonest type of primary localized cutaneous amyloidosis. Its etiology is unknown but chronic irritation to the skin has been proposed as an etiological factor.[4] The amyloid deposits in LA are mainly restricted to the upper dermis and arise because of focal epidermal damage with subsequent conversion of necrotic keratinocytes into amyloid in the papillary dermis.[5] The condition persists for many years with pruritus, but a non-itchy variant has also been reported. Treatment options include potent topical steroids under occlusion, intralesional steroids, topical dimethylsulfoxide and etretinate.[6] Surgical modalities of treatment include dermabrasion and scalpel scraping[7] of the lesions. We found a male preponderance, and pruritus the presenting symptom in 27 (90%) cases [Table - 2]. Fifty per cent of our patients presented during the winter. A genetic predisposition along with winter dryness may probably be predisposing factors in LA. Seventeen patients (56.7%) gave a history of using a scrub while bathing for more than two years, establishing the role of friction in LA. In South India the use of nylon wire brush and coconut fibre is extremely popular among the ladies.[10],[11] There was a family history of LA in 20% of the cases. An autosomal dominant mode of transmission has been reported.[12],[13] The pretibial area was the commonest site of involvement in our study. This has been found by all other studies[1],[8],[14] [Table - 3] except for the one by Al Ratrout.[9] Involvement of the face, neck, buttocks and axilla has also been reported.[15] Textile contact dermatitis may also present as LA on areas covered by clothing and such patients should be patch tested with textile colors and finishing series.[16] The sensitivity of Congo red staining in detecting amyloid was 100% while that of histopathology was 93.3%. Perifollicular amyloid deposits are a hitherto unreported finding. Our findings showed the presence of IgM, C3, and IgA in all patients, as have earlier studies [Table - 4].[17] Lichen amyloidosus is an extremely pruritic dermatosis, most common site of involvement being the shins. Clinical and histopathological examinations are helpful in detection in majority of cases which can further be supplemented by immunofluorescence studies. REFERENCES
Copyright 2005 - Indian Journal of Dermatology, Venereology and Leprology The following images related to this document are available:Photo images[dv05054t4.jpg] [dv05054f2.jpg] [dv05054f1.jpg] [dv05054t3.jpg] [dv05054t1.jpg] [dv05054t2.jpg] [dv05054f3.jpg] |
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