lichen planus pigmentosus usually presents as diffuse grayish hyperpigmented macules over the trunk and flexure aspects of extremities , but reticular , blotchy , and perifollicular forms are also seen . lichen planus pigmentosus is seen in indian , latin - american , and other dark - skinned populations , presenting as ill - defined , grayish hyperpigmented macules commonly affecting the face and neck . we report a case of an elderly woman , who presented with generalized reticulate pigmentation and scarring alopecia , in which a diagnosis of poikilodermatous lichen planus pigmentosus was established on the basis of dermoscopic and histological findings . a 70-year - old woman presented with a 25-year history of reticulate pigmentation over the trunk and extremities . for the past 20 years , she also complained of erythema and burning sensation on exposure to sunlight . she also developed a loss of hair from the scalp and eyebrows with few itchy violaceous scaly plaques over the trunk and extremities in the past 10 years . there was no history of muscle weakness , oral ulcers , and joint pain . on examination , there was brownish reticulate pigmentation in a generalized distribution involving the trunk and extremities , sparing the mid - face . she also had scarring alopecia of the frontoparietal scalp and nonscarring alopecia of the eyebrows , axilla , and groin [ figure 1b ] . in addition , there were multiple , discrete , well - defined , 34 cm - sized , violaceous , scaly plaques over the trunk and forearm [ figure 1c ] . oral cavity , palms , soles , nails , and genitals were found to be normal . ( a ) generalized brownish reticulate pigmentation involving the trunk and extremities with few skip areas on the chest . ( c ) multiple , discrete , well - defined , 34 cm - sized , violaceous , scaly plaques over the trunk and forearm , resolving with reticulate pigmentation her routine hematological and biochemical investigations were within normal limits . antinuclear antibodies , anti - double - stranded dna antibodies , muscle enzymes , 24 h urine protein analysis , and computed tomography scan of the chest and abdomen were found to be normal . her skin biopsy from the reticulate hyperpigmented plaque showed atrophic epidermis and multiple dilated , congested capillaries in the papillary dermis [ figure 2a ] . biopsy from the alopecic patch over the scalp revealed epidermal atrophy and papillary dermal sclerosis with pigment incontinence . a skin biopsy from violaceous plaque showed compact hyperkeratosis , parakeratosis , irregular acanthosis , and mild papillary dermal fibrosis . a band - like lichenoid infiltrate was seen in the upper dermis at one end of the section . there was basal cell damage in this area with occasional necrotic keratinocytes and dermal melanophages . dermoscopic evaluation ( heine mini 3000 , nonpolarized , model no .- d-886.11.021 , germany ) of the reticulate plaque over the chest showed the presence of dots and globules in a reticular pattern with the presence of atrophy and multiple telangiectasias [ figure 2d ] . based on the clinical , histological , and dermoscopic findings , a final diagnosis of poikiloderma due to lichen planus pigmentosus was made , and she was administered oral prednisolone ( 40 mg ) which resulted in a significant improvement in pruritus and visible flattening of violaceous plaques within 1 month of the treatment . prednisolone was gradually tapered after an improvement was seen in itchy plaques , and to some extent in hair growth , however , poikiloderma continued to persist . hematoxylin and eosin stain of the skin biopsy ( a , 200 ) from the reticulate pigmentation over the back showed epidermal atrophy and multiple , dilated , congested capillaries ( b , 200 ) , ( c , 400 ) from the violaceous plaque over the back showed basal cell damage , pigment incontinence , and lichenoid infiltrate in the papillary dermis . ( d ) dermoscopy ( heine mini 3000 , nonpolarized , 10 ) of the reticulate plaque showed reticulate pigmentation , atrophy , and telangiectasias the most common pattern described for lichen planus pigmentosus is diffuse grayish hyperpigmented macules over the trunk and flexure aspects of extremities , but reticular , blotchy , and perifollicular forms are also seen . our patient presented with generalized reticulate pigmentation over the face , trunk , and extremities associated with scarring alopecia of the scalp and nonscarring alopecia of the body hairs . we considered an initial clinical diagnosis of poikiloderma due to cutaneous t - cell lymphoma , which was ruled out on the basis of histological and dermoscopic findings . similarly , poikiloderma due to connective tissue disease was thought as a second differential diagnosis , but was not supported by the investigations . lassueur syndrome was considered due to the presence of scarring alopecia of the scalp and nonscarring alopecia of the body , but follicular keratosis pilaris - like lesions were not seen . the presence of violaceous itchy plaques over the trunk , lichenoid changes in the histopathology , dermoscopic evaluation of the reticulate plaques showing reticular pigmentation , and atrophy with telangiectasia helped us to confirm our diagnosis . association of these three presentations of lichen planus is rare where typical lichen planus lesions were seen in addition to the poikilodermatous lesions of lichen planus pigmentosus and cicatricial alopecia . our case showed the presence of reticulate pigmentation ; atrophy and telangiectasia could be demonstrated with the dermoscopic and histological evaluation . lin et al . , where clinically , reticulate pigmentation was seen in the absence of atrophy and telangiectasia . involvement of the scalp in the form of diffuse scarring alopecia with this cutaneous presentation is rarely reported . poikilodermatous form of lichen planus pigmentosus , associated with typical lichen planus lesions and cicatricial alopecia , is rare . poikilodermatous form of lichen planus pigmentosus , associated with typical lichen planus lesions and cicatricial alopecia , is rare . poikilodermatous form of lichen planus pigmentosus , associated with typical lichen planus lesions and cicatricial alopecia , is rare .
a 70-year - old woman presented with generalized reticulate pigmentation , scarring alopecia , and few discrete , violaceous plaques over the trunk and forearm . 
 dermoscopic evaluation of the reticulate plaque showed reticulate hyperpigmentation with multiple telangiectasias , and skin biopsy showed lichenoid interface dermatitis with marked pigment incontinence . 
 thus , a final diagnosis of poikiloderma due to lichen planus pigmentosus was considered .