Indian Journal of Dermatopathology and Diagnostic Dermatology

CASE REPORT
Year
: 2019  |  Volume : 6  |  Issue : 1  |  Page : 45--47

Amyloidosis cutis dyschromica: A rare dyschromic pigmentary disorder


Kuldeep Verma1, Reena Kumari Sharma1, Anchana Gulati2, Mudita Gupta1,  
1 Department of Dermatology, Venereology and Leprosy, Indira Gandhi Medical College, Shimla, Himachal Pradesh, India
2 Department of Pathology, Indira Gandhi Medical College, Shimla, Himachal Pradesh, India

Correspondence Address:
Dr. Mudita Gupta
Department of Dermatology, Venereology and Leprosy, Indira Gandhi Medical College, Shimla, Himachal Pradesh
India

Abstract

Primary cutaneous amyloidosis (PCA) is the deposition of amyloid proteins in the skin without systemic involvement. Amyloidosis cutis dyschromica (ACD) is a rare variant of PCA with onset typically in early childhood or at a prepubertal age. It is more common in the Asian and Southeast Asian people. Clinically it manifests as asymptomatic diffuse hyperpigmentation interspersed with hypopigmented spots without papulation. Histologically, small foci of amyloid closely under the epidermis are seen. There are only few case reports in the literature of this rarer variant. We report a case of a 32-year-old male presenting as dyschromatosis with a prepubertal onset and histopathological evidence of intradermal deposits in the upper dermis which was confirmed on Congo red staining and hence was diagnosed as a case of ACD.



How to cite this article:
Verma K, Sharma RK, Gulati A, Gupta M. Amyloidosis cutis dyschromica: A rare dyschromic pigmentary disorder.Indian J Dermatopathol Diagn Dermatol 2019;6:45-47


How to cite this URL:
Verma K, Sharma RK, Gulati A, Gupta M. Amyloidosis cutis dyschromica: A rare dyschromic pigmentary disorder. Indian J Dermatopathol Diagn Dermatol [serial online] 2019 [cited 2022 Aug 13 ];6:45-47
Available from: https://www.ijdpdd.com/text.asp?2019/6/1/45/260188


Full Text



 Introduction



Amyloidosis cutis dyschromica (ACD) is a rare variant of primary cutaneous amyloidosis (PCA) which was first described by Morishima in 1970.[1] It has prepubertal onset and presents as generalized hyperpigmented interspersed with hypopigmented or depigmented macules of varying sizes, which may be asymptomatic or associated with minimal pruritus.[2] This is a rare variant of PCA with <50 cases reported in the literature.[3] We report a case of a 32-year-old male who presented to us with diffuse hyperpigmentation with hypopigmented macules at places which was diagnosed as a case of ACD.

 Case Report



A 32-year-old Indian male presented to us with hypopigmented and hyperpigmented lesions all over the body for the past 20 years. The lesions were asymptomatic and were initially localized to proximal extremities. Over a period of 5–6 months, lesions progressed to involve the trunk. There was no history of photosensitivity or blistering. There was no history suggestive of easy fatigability, purpuric lesions, easy bruisability, recurrent infections, or any other systemic complaint. He was born to nonconsanguineous parents with unremarkable birth and developmental history. There was no pigmentary or cutaneous complaint in any of the two siblings or other family members. On examination, he was a young male of average built without any clinical evidence of anemia or other nutritional deficiency. On a background of diffuse hyperpigmentation, there were guttate hypopigmented/depigmented macules of size ranging from 0.5 cm × 0.5 cm to 1 cm × 1 cm over the trunk and extremities [Figure 1]. No freckles, blisters, atrophy, or telangiectasia was seen. Face, hands/feet, and flexures were spared. There was no evidence of any connective tissue disease. There was no involvement of hair, teeth, nails, oral mucosa, eyes, ear, or any other system. Clinical possibility of ACD and dyschromatosis universalis hereditaria (DUH) was kept. Blood investigations including complete blood count, liver, renal function tests, and serum electrolytes were within the normal limits. Skin biopsy from the trunk showed relatively normal epidermis with orthokeratosis. There were widened papillae with deposition of globular pink deposits in the interface region in association with occasional melanophages suggestive of amyloidosis [Figure 2]. Congo red stain for amyloidosis was positive [Figure 3]. The findings were suggestive of ACD. The patient was started on tablet acitretin 25 mg twice a day and is under follow-up.{Figure 1}{Figure 2}{Figure 3}

 Discussion



Amyloidosis is an abnormal extracellular deposition of amyloid, a fibrillar proteinaceous material within tissues. The proteins are converted from their soluble state to insoluble one which forms the amyloid. PCA is the deposition of amyloid in previously apparent normal skin with no systemic involvement. There are mainly three types of PCA – macular, papular, and nodular. Macular amyloidosis is the most common variant, usually presenting on the back and extensors. Macular and papular amyloidosis are associated with hyperpigmentation and pruritus in a localized distribution. Rare variants include familial poikiloderma-like cutaneous amyloidosis, bullous, vitiliginous, anosacral, and ACD.[4]

Inheritance in ACD is usually autosomal dominant but sporadic cases may be seen as in our patient.[3] Clinically, ACD is characterized by the following features: mottled hyperpigmented, and hypopigmented (diffuse, reticulate, or dotted) and/or depigmented macules of varying sizes all over the body, onset before puberty, usually nonpruritic or mildly pruritic lesions and focal amyloid deposition in papillary dermis on histopathology.[4]

The pathogenesis of ACD is not very clear. Genetic factors have been implicated as it occurs before puberty and shows a familial predilection.[5] Ultraviolet B (UVB) and UVC-induced damage to keratinocytes is said to take a longer time for repair in ACD. The destroyed keratinocytes due to delayed DNA repair undergo apoptosis. The phagocytosed cytokeratin is responsible for the amyloid formation.[5] Photodamage is thought to be triggering factor but predisposition of trunk involvement cannot be explained. In contrast to other cutaneous amyloidosis where pruritus is a triggering factor, ACD is usually nonitchy, so neurogenic factors are less likely to be implicated.

Sequestration of melanin from epidermis to dermis and engulfment by macrophages may contribute to hyperpigmentation. Subepidermal amyloid deposits lead to altered melanocyte density. At the same time, the melanocyte and keratinocyte ratio is disturbed because of increased sensitivity of melanocytes to damage by ultraviolet rays.[6]

Clinically, ACD resembles dyschromias including DUH, familial poikiloderma-like cutaneous amyloidosis, xeroderma pigmentosum, chronic arsenic exposure, and drug-induced dyschromatosis.[2],[7] Histopathologically, these clinical entities can be differentiated from ACD by the absence of amyloid deposits. Poikiloderma-like amyloidosis may have similar amyloid deposits along with poikilodermatous features but clinically may be associated with light sensitivity, short stature and blister formation, lichenoid papules, palmoplantar hyperkeratosis and appear in adult life.[8] Various drugs tetracycline, diphenylcyclopropenone, thiazides, monobenzyl ether of hydroquinone, and afloqualone can cause dyschromatosis, but our patient had spontaneous onset of disease.

Various treatments have been used with variable results. Sun avoidance and protection, topical corticosteroids, keratolytics, dimethyl sulfoxide, capsaicin, and carbon dioxide laser have been tried.[5] However, systemic acitretin has been reported to have good response. Acitretin-induced apoptosis may reduce the available cytokeratin, the most probable source of amyloid.[9]

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients 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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