cutaneous amyloidosis were classified into primary cutaneous amyloidosis ( pca ) , secondary cutaneous amyloidosis , and systemic cutaneous amyloidosis .
pca is a rare , chronic progressive skin disease , defined as deposition of amyloid in previously apparent normal skin without systemic involvement .
its prevalence were rarely reported . until now , there are fewer than 40 published cases worldwide .
etiological factors associated with pca is still unknown , but its striking familial occurence suggests the role of genetic .
we report a case with peculiar mottled pigmentation originally referred for vitiligo , but later proved as acd by histopathological examination .
the disorder was thought to be familial as his siblings were affected with the similar condition .
a 12-year - old boy presented with asymptomatic , generalized mottled hypo- and hyper - pigmented lesions of 6-year duration .
the hypopigmented macules were first noticed on his lower extremities and had been slowly progressing to involve almost the entire body ( figure 1a ) .
he did not have any history of systemic or cutaneous disease before the onset of the lesions .
history of trauma , rubbing of the skin with any material , and extensive sun exposure was denied .
his 11-year - old sister and 6-year - old brother experienced similar yet milder symptoms .
physical examination revealed an extensive , discrete , pigmented macules distributed nearly all over the body in symmetrical pattern .
he was referred to our hospital for skin biopsy with the initial differential diagnoses of vitiligo and pityriasis alba .
histopathological examination ( figure 2 ) showed uneven distribution of melanin in the epidermis and deposits of pale pink amorphous material in the papillary dermis .
based on clinical presentation and the histopathology examination , we made the diagnosis of primary cutaneous amyloidosis , presented as amyloid cutis dyschromica .
the patient was treated with oral acitretin 25 mg per day . by the third month
, some improvement was observed as the pigmented macules were slightly lightened ( figure 1b ) .
the patient could tolerate the treatment , as there was no significant increase of transaminases and the lipid profile .
the diagnosis of acd in our patient was not readily recognized as it mimicked , to some degree , other relatively common disorders with pigmentation feature .
that , combined with its low prevalence , had eluded previous attempts at the correct diagnosis and treatment .
the peculiar asymptomatic mottled pigmentation is much likely seen in poikiloderma , but as our case showed , without the corresponding signs such as telangiectasia or atrophy . furthermore , our patient was otherwise healthy , showing no signs that might indicate systemic disorders or photosensitivity , e.g. dermatomyositis , lupus erythematosus , or xeroderma pigmentosum .
as defined by morishima , acd characterized by diffuse speckled hyperpigmentation with hypopigmented spots without papulation , atrophy , and telagiectasia , mild or no itching , onset before puberty , and focal amyloid deposition in the papillary dermis .
duh begins in infancy or childhood , and unlike acropigmentation of dohi , might encompass the whole skin surface with exception of face . for definite diagnosis , histopathologic examination should be shought .
the most common epidermal findings of pca were hyperkeratosis , irregular acanthosis with thinning of rete ridges , and expansion of dermal papillae by amyloid deposition .
the finding of amyloid bodies in the papillary dermis was crucial in establishing the diagnosis of acd in our patient and disproved duh , in which such deposition was absent .
its visualization under polarized light , showing apple - green birefrigence , confirmed the presence of amyloid .
special histochemical stains were helpful for confirming the existence of amyloid . in our case ,
we tried to obtain histopathological examination of the siblings , but the parents denied the request to perform biopsy on the grounds that their clinical appearances were quite similar that the histopathological findings would likely be the same .
multiple factors such as race , genetic , and enviromental may play collective roles , making variable degrees of cutaneous amyloidosis .
although most cases of acd were sporadic , many have also reported positive family history of pca , suggesting that the important role of genetic factors in its pathogenesis .
our patient s siblings experienced similar yet milder symptoms that the disorder was thought to be familial .
, familial relationship was found in 5 of 10 patients , and consanguinity was denied in all .
amyloidosis cutis dyschromica is assumed to be a congenital disorder and exposure to sunlight is thought to be the major causal factor .
the lesions in our patient were more pronounced on exposed parts of body , that we thought sun exposure might be an important cause .
acitretin was given and seems to be effective because it may act by minimizing keratinization defect that causes keratin degeneration to amyloid as proposed by some to be the pathogenesis of this disorder .
qiao et al . in his series has convincingly shown 100% positivity to immunohistochemical staining for keratin , ck34 e12 and ck5/6 , that the amyloid is thought to be of epidermal origin .
that points at a disturbance of keratinocyte repairs after irradiation with ultraviolet . at the third month
his serum transaminase and lipid profile were only slightly increased , that we think the drug was safe to be continued .
however , it is interesting to note that some authors consider certain populations of asia , e.g. chinese , japanese and thai , particularly susceptible .
therefore , it is possible that several cases of this elusive disorders exist , but are often misdiagnosed . on the other hand , the treatment of acd still remains a challenge .
 amyloidosis cutis dyschromica ( acd ) is an extremely rare type of primary cutaneous amyloidosis . to date 
 there are fewer than 40 published cases worldwide ; some were reported affecting several family members . 
 its resemblance to other common pigmentation disorders makes it rarely recognized at first sight . 
 our patient , the 12-year - old firstborn son of non - consanguineous parents presented with generalized mottled pigmentation starting from lower extremities . 
 his siblings suffered from similar condition . 
 the clue for diagnosis is the amyloid deposition in the papillary dermis . 
 the etiology of acd is still unknown , but genetic factors and ultraviolet radiation are implicated . 
 it is proposed that disturbance of keratinocyte repair following ultraviolet radiation results in amyloid deposition . 
 the treatment remains a challenge . 
 oral acitretin treatment , thought to repair keratinization defect , gave a slight improvement in our case . 
 our is the first case of acd reported in indonesia . 