Cutaneous amyloidoses

Fibulin-4 accelerates amyloid formation through binding with a keratin 5 peptide fragment

Keratins are the major amyloid fibril component in localized cutaneous amyloidosis. We analyzed the amyloid components in the skin of patients with localized cutaneous amyloidosis by immunohistochemical staining using antisera against extracellular matrix proteins and keratin 5 (K5). Fibulin-4 and K5 colocalized in the amyloid deposits. Using 14 synthetic peptides, we screened for amyloidogenic sequences in the C-terminal region of K5, including the α-helical rod domain and the tail domain. Two peptides stained with thioflavin T possessed a β-sheet structure and formed amyloid-like fibrils. Among the amyloidogenic peptides, a peptide KT5-6 (YQELMNTKLALDVEIATYRKLLEGE) derived from the α-helical rod domain of K5 specifically bound to fibulin-4. In addition, amyloid formation of KT5-6 was accelerated by fibulin-4. These results suggest that degraded fragments of K5 containing the KT5-6 sequence form amyloid fibrils with fibulin-4. The data further suggest that degraded fragments of K5 and fibulin-4 have the potential to initiate cutaneous amyloidosis.

Role of sequential chemical peel in cutaneous amyloidosis: a pilot case series

Cutaneous amyloidosis can be a part of a systemic disease or can result from a localized process limited to the skin. It usually presents as pruritic hyperpigmented macules, papules or nodules, which are notoriously resistant to treatment. We performed a hospital-based pilot case series to assess the efficacy and safety of sequential salicylic acid (SA) and glycolic acid (GA) chemical peels. Patients underwent sequential chemical peel therapy with SA 20% and GA 35% used alternately each week for a total of 6 weeks. At subsequent follow-up visits, good clinical outcome and long-term maintenance was observed. This study highlights the promising role of chemical peels in this difficult and distressing disorder.

A clinico-epidemiological study of macular amyloidosis from north India

BACKGROUND

Macular amyloidosis (MA) is the most subtle form of cutaneous amyloidosis, characterized by brownish macules in a rippled pattern, distributed predominantly over the trunk and extremities. MA has a high incidence in Asia, Middle East, and South America. Its etiology has yet to be fully elucidated though various risk factors such as sex, race, genetic predisposition, exposure to sunlight, atopy and friction and even auto-immunity have been implicated.

AIM

This study attempts to evaluate the epidemiology and risk factors in the etiology of MA.

MATERIALS AND METHODS

Clinical history and risk factors of 50 patients with a clinical diagnosis of MA were evaluated. Skin biopsies of 26 randomly selected patients were studied for the deposition of amyloid.

RESULTS

We observed a characteristic female preponderance (88%) with a female to male ratio of 7.3:1, with a mean age of onset of MA being earlier in females. Upper back was involved in 80% of patients and sun-exposed sites were involved in 64% cases. Incidence of MA was high in patients with skin phototype III. Role of friction was inconclusive

CONCLUSION

Lack of clear-cut etiological factors makes it difficult to suggest a reasonable therapeutic modality. Histopathology is not specific and amyloid deposits can be demonstrated only in a small number of patients. For want of the requisite information on the natural course and definitive etiology, the disease MA remains an enigma and a source of concern for the suffering patients.

Acquired reactive perforating collagenosis: current status

Acquired reactive perforating collagenosis is a unique perforating dermatosis, characterized clinically by umbilicated hyperkeratotic papules or nodules and histologically by a focal hyperkeratosis in direct contact with transepidermal perforating dermal collagen. Several inflammatory or malignant systemic diseases may coexist with acquired reactive perforating collagenosis. The possible biochemical or immunological mechanisms of the systemic diseases, potentially responsible for the development and appearance of acquired reactive perforating collagenosis, are still under investigation. Several topical treatments, ultraviolet B phototherapy and allopurinol p.o. administration may be effective.

The Asian dermatologic patient: review of common pigmentary disorders and cutaneous diseases

The Asian patient with Fitzpatrick skin types III-V is rarely highlighted in publications on cutaneous disorders or cutaneous laser surgery. However, with changing demographics, Asians will become an increasingly important group in this context. Although high melanin content confers better photoprotection, photodamage in the form of pigmentary disorders is common. Melasma, freckles, and lentigines are the epidermal disorders commonly seen, whilst nevus of Ota and acquired bilateral nevus of Ota-like macules are common dermal pigmentary disorders. Post-inflammatory hyperpigmentation (PIH) occurring after cutaneous injury remains a hallmark of skin of color. With increasing use of lasers and light sources in Asians, prevention and management of PIH is of great research interest. Bleaching agents, chemical peels, intense pulsed light (IPL) treatments, and fractional skin resurfacing have all been used with some success for the management of melasma. Q-switched (QS) lasers are effective for the management of epidermal pigmentation but are associated with a high risk of PIH. Long-pulsed neodymium-doped yttrium aluminum garnet (Nd:YAG) lasers and IPL sources pose less of a PIH risk but require a greater number of treatment sessions. Dermal pigmentary disorders are better targeted by QS ruby, QS alexandrite, and QS 1064-nm Nd:YAG lasers, but hyper- and hypopigmentation may occur. Non-ablative skin rejuvenation using a combination approach with different lasers and light sources in conjunction with cooling devices allows different skin chromophores to be targeted and optimal results to be achieved, even in skin of color. Deep-tissue heating using radiofrequency and infra-red light sources affects the deep dermis and achieves enhanced skin tightening, resulting in eyebrow elevation, rhytide reduction, and contouring of the lower face and jawline. For management of severe degrees of photoaging, fractional resurfacing is useful for wrinkle and pigment reduction, as well as acne scarring. Acne, which is common in Asians, can be treated with topical and oral antibacterials, hormonal treatments, and isotretinoin. Infra-red diode lasers used with a low-fluence, multiple-pass approach have also been shown to be effective with few complications. Fractional skin resurfacing is very useful for improving the appearance of acne scarring. Hypertrophic and keloid scarring, another common condition seen in Asians, can be treated with the combined used of intralesional triamcinolone and fluorouracil, followed by pulsed-dye laser. Esthetic enhancement procedures such as botulinum toxin type A and fillers are becoming increasingly popular. These are effective for rhytide improvement and facial or body contouring. We highlight the differences between Asian skin and other skin types and review conditions common in skin of color together with treatment strategies.

A study of cytokeratin profiles in localized cutaneous amyloids

The major component of localized cutaneous amyloids may be derived from cytokeratin (CK). However, the CK profiles of primary cutaneous amyloidosis (PCA) and secondary cutaneous amyloidosis (SCA) remain obscure. Paraffin-embedded sections of skin tissue from 64 patients with PCA, 111 with SCA and 3 with systemic amyloidosis were analyzed immunohistochemically using 12 different polyclonal or monoclonal anti-CK antibodies (34betaE12, MNF116, LP34, AE1/AE3, anti-CK1, CK5, CK6, CK7, CK10, CK14, CK16 and CK17). In addition, frozen skin tissues from 12 patients with PCA were analyzed for comparison with the paraffin-embedded tissue. In all 64 PCA paraffin sections, the amyloid deposits were immunopositive for anti-CK5 antibody and 34betaE12. In all 12 frozen sections of PCA, the amyloid deposits were immunopositive for anti-CK5 antibody, 34betaE12, MNF116 and LP34, and seven (58.3%), three (25%) and one (8.3%) were immunopositive for anti-CK1, CK14, and CK10 antibodies, respectively. In all SCA sections, the amyloid deposits were immunopositive for CK5 and 34betaE12. In addition, MNF116 immunolabeled amyloids of all sections from patients with basal cell carcinoma and trichoepithelioma, and MNF116 and LP34 immunolabeled amyloids of sections from patients with porokeratosis. Our results indicate that CK5 is the major CK present in the amyloid deposits of PCA and SCA, and "amyloid-K" is mainly derived from basal keratinocytes.

Cutaneous diseases in Asians

Atopic dermatitis, nummular dermatitis, dyshidrosis, and melasma seem to be more common in Asians, whereas psoriasis and skin cancer are less common. In addition, there are less common skin conditions that are usually seen in Asians, including Mongolian spot, nevus of Ota, nevus of Ito, Kawasaki disease, primary cutaneous amyloidosis, Kikuchi-Fujimoto disease, and LCAI. Awareness of these less common cutaneous disorders can be helpful, especially for clinicians who work in areas with a large Asian population.

Frictional amyloidosis: a study of 10 cases

Ten patients with macular amyloidosis were studied with particular reference to the role of friction. All 10 patients had a history of prolonged rubbing over a period of 2-5 years with various objects, such as bath sponges, brushes, towels, plant sticks and leaves. The presence of amyloid was confirmed by histochemical stains in six cases and by electron microscopy in four cases. The study confirms the role of friction in the causation of macular amyloidosis and hence, the term 'frictional amyloidosis' aptly describes the condition. The study also emphasizes the need for electron microscopy in the diagnosis of frictional amyloidosis.

Anosacral cutaneous amyloidosis: a study of 10 Chinese cases

BACKGROUND

Primary cutaneous amyloidoses are rare in Western countries, but are relatively common in Taiwan. Anosacral cutaneous amyloidosis is a rare type of primary cutaneous amyloidoses, first reported in Japanese patients.

PATIENTS/METHODS

In the present study, we investigated the age of onset, sites of involvement, associated systemic diseases, and histopathological findings in 10 cases of anosacral cutaneous amyloidosis seen during the past 27 years.

RESULTS

In previous reports the aetiology of anosacral cutaneous amyloidosis was thought to be a senile change, but half of our patients developed the disease before the age of 60 years. Based on our histopathological findings, apoptosis may be the initial event causing amyloid deposition, although the precise mechanism causing apoptosis needs further investigation. Three patients were found to have diabetes mellitus, but any relationship to anosacral cutaneous amyloidosis is unclear.

CONCLUSIONS

No cases of this cutaneous disorder have been reported in the Western literature; there seems to be a racial difference accounting for the disease, although the precise factor is not clarified yet. The disease could easily be misdiagnosed as lichen simplex chronicus, postinflammatory hyperpigmentation or tinea cruris; therefore, a thorough history, a careful physical examination and a skin biopsy is needed to establish a firm diagnosis.

Macular amyloidosis: etiological factors

Macular amyloidosis is the commonest form of primary localized cutaneous amyloidosis; its etiology remains unclear. Various incriminating factors include genetics, sunlight, and friction. Seventy-five patients with a clinical diagnosis of macular amyloidosis (confirmed by at least two observers) were enrolled in the study. A detailed history was elicited in relation to the etiological factors and followed by cutaneous examination. Skin biopsy was performed in 44 patients. Amyloid deposits were demonstrated in 21 (48%) of the biopsies. The female to male ratio was over 3:1. Patients with skin type V had a more delayed onset than those with skin types III and IV. Two patients gave histories of regularly subjecting their skin to friction. There was no correlation between the sites affected and the sites subjected to friction, hair style of the patient, or the use of cosmetics. Family history was present in 7 (9.3%) patients. A majority, 44 (58.7%) of the patients, had involvement of both sun-exposed and sun-protected sites. To conclude, there was no direct correlation between macular amyloidosis and atopy, sunlight, or friction to the skin in our patients. Multiple factors may play a collective role in the genesis of macular amyloidosis to variable degrees. These include racial, familial, and environmental factors, atopy, sunlight, friction, and female gender.

Apoptosis in primary cutaneous amyloidosis

Amyloid deposits in primary cutaneous amyloidosis (PCA) may be initially derived from cytokeratin. possibly after keratinocyte death. However, the mechanism of keratinocyte death remains obscure. To investigate the potential role of apoptosis in the pathogenesis of PCA, a retrospective study was conducted on the skin tissues from 20 Chinese patients with PCA. We used a terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labelling (TUNEL) method for detecting the apoptotic cells. Immunohistochemical staining was performed to examine the expression of the B-cell leukemia/lymphoma-2 gene (bcl-2) and Fas. Apoptotic cells were shown in 11 of 20 cases (55%) by TUNEL. Histological sections showed that dyskeratotic cells and vacuolar alteration of the basal cells were more commonly observed in the TUNEL-positive group. In all cases of PCA, epidermal expression of bcl-2 was minimal, while expression of Fas was observed on keratinocytes in the basal to granular layers: however, these findings were not different from those in normal skin. Our results suggest that the keratinocyte destruction in PCA may occur as an initial result of apoptosis, which in turn leads to the amyloid formation.

Inflammatory linear verrucose epidermal nevus coexisting with lichen amyloidosus

The clinical and histopathological findings in a case of inflammatory linear verrucose epidermal nevus coexisting with lichen amyloidosus are presented. A 33-year-old woman had had linear verrucose lesions which were histopathologically compatible with ILVEN, and with which no amyloid deposits were associated, on her left lower leg for 30 years. She had noticed keratotic papules around the verrucose lesions on the left leg for the last 3 years. Histopathology of these papules revealed amyloid deposits in the upper dermis under the hyperkeratotic and acanthotic epidermis. Topical application of DMSO liniment with dexamethasone successfully treated the ILVEN. This remission of both lesions and itching also alleviated the keratotic papules on the left leg.

Extensive lichen amyloidosus refractory to DMSO

While lichen amyloidosus reportedly may respond to dimethyl sulfoxide (DMSO) application, we present a patient whose lesions were refractory to this agent. This Japanese woman had chronic extensive lichen amyloidosus, mainly on her trunk. Her 10-year history of using nylon towels was the suspected cause. The application of DMSO ointment had no clinical effect, and the amyloid deposits persisted in the histological specimens despite the treatment. The administration of a topical corticosteroid led to gradual clinical improvement.

Friction amyloidosis: a variant or an etiologic factor in amyloidosis cutis?

BACKGROUND

During a study of cutaneous amyloidosis, it was noticed that a significant number of patients gave a history of friction of some kind or other, which when analyzed could be clearly related to their cutaneous pigmentation. A common feature in all these patients was the relative lack of itching when compared with others who did not give a history of friction.

METHODS

We studied the role of friction in 65 patients with amyloidosis cutis and found that in 20 patients, frictional factors could be attributed to their cutaneous condition, and these latter were taken up for further study.

RESULTS

Histologic examination of the affected area of skin showed amyloid deposits, which could be detected by light microscopy with hematoxylin and eosin stained sections and confirmed by special stains.

CONCLUSIONS

The role of friction in the causation of lesions that resemble amyloidosis cutis morphologically is discussed.

Therapy of amyloid diseases

Deposition of amyloid in the organism can lead to severe clinical symptoms and syndromes which are referred to as amyloidosis. However, amyloidosis is not a pathogenetically single disease entity. Various amyloid diseases are known which can clearly be distinguished by identifying the protein from which the amyloid is derived. Since the amyloid syndromes are pathogenetically diverse, each of the different amyloid diseases needs to be treated differently, and a type-specific amyloid therapy is mandatory. Unfortunately, an efficient therapy is not yet available for most amyloid syndromes. It is the purpose of this review to show how the different amyloid syndromes are distinguished definitively from each other and what has been successful in the effort to establish an efficient therapy of the various amyloid deposits and different amyloidoses.

Unusual manifestations of primary cutaneous amyloidosis in association with Raynaud's phenomenon and livedo reticularis

A patient with unusual manifestations of primary cutaneous amyloidosis, including macules, papules, oedematous plaques and urticarial lesions is described. Raynaud's phenomenon and livedo reticularis were an associated finding. During the acute phase, single doses of systemic corticosteroids resulted in an impressive, long-lasting improvement in cutaneous manifestations.

Primary localized cutaneous amyloidosis

Fifty-seven patients with primary localized cutaneous amyloidosis (PLCA) were clinically and histopathologically reviewed. Two-thirds of patients had macular amyloidosis (MA). Intermediate cases having macular lesions with micropapules and/or lichens were identified. A spectrum for the disease is proposed, in which the less itchy classical macular variant occurs at one end and the very pruritic traditional lichen variant at the other. The salient histopathologic findings were similar in the macules, micropapules, and lichens, but were more prominent in the lichens. These consisted of hyperkeratosis, keratinocyte degeneration, satellite cell necrosis, and basal cell destruction. Amyloid deposition in the dermal papillae with transepidermal elimination, dermal melanophages, and superficial perivascular inflammation were also present. These changes represent an interface dermatitis of the vacuolar type. PLCA may be categorized under the group of dermatoses characterized by a lichenoid tissue reaction; inflammation may play a key role in mediating these disorders.

Skin deposits in hereditary cystatin C amyloidosis

Clinically normal skin from 47 individuals aged 9-70 years was investigated. Cystatin C amyloid deposits were found in various locations of the skin by light and/or electron microscopy, in all 12 patients with a clinical history of hereditary cystatin C amyloidosis (HCCA). Six asymptomatic individuals, who had the Alu 1 restriction fragment length polymorphism (RFLP) marker reported to cosegregate with the disease, also had cystatin C amyloid deposits in the skin. Three asymptomatic individuals (age 17-46) belonging to the HCCA families were without amyloid in the skin but had Alu 1 RFLP marker. Skin from 12 individuals who served as controls and skin from 14 close relatives of the patients was negative for amyloid. Punch biopsy of the skin is a simple procedure which is of value for the diagnosis of HCCA, even before the appearance of clinical symptoms. This method might also be of use in following progression of the disease.

Unilateral facial actinic elastotic plaque--a new clinical variant of actinic elastosis

The case is reported of an 82-year old woman with a four month history of an erythematous indurated plaque on the left cheek. Light and electron microscopy demonstrated the presence of solar elastosis alone. We believe that this is a new clinical variant of solar elastosis. The spectrum of cutaneous actinic damage is reviewed.

Friction amyloidosis

Three patients developed a peculiar pigmentation arising from prolonged mechanical friction with the skin due to the use of rough nylon towel or back scratcher for many years. Histochemical stains could not show the existence of amyloid in one of the cases, but amyloid deposition was identified in successive electron microscopic investigations in all three cases. Although "friction melanosis" was originally used by others to describe a close relationship between friction and skin pigmentation in a similar disorder, we consider the term "friction amyloidosis" more appropriate for specifying the important role of friction in causing the early stage of macular amyloidosis. Electron microscopic examination is of importance in establishing a firm diagnosis of this disorder.