Lichen amyloidosus: a consequence of scratching

Unmet needs in treating itch: reaching beyond eczema

PURPOSE

Pruritus is an unpleasant sensation that creates the urge to scratch. In many chronic conditions, relentless pruritus and scratching perpetuates a vicious itch-scratch cycle. Uncontrolled itch can detrimentally affect quality of life and may lead to sleep disturbance, impaired concentration, financial burden, and psychological suffering. Recent strides have been made to develop guidelines and investigate new therapies to treat some of the most common severely pruritic conditions, however, a large group of diseases remains underrecognized and undertreated. The purpose of this article is to provide a comprehensive review of the challenges hindering the treatment of pruritus.

METHODS

An online search was performed using PubMed, Web of Science, Google Scholar, and ClinicalTrials.gov from 1994 to 2024. Included studies were summarized and assessed for quality and relevance in treating pruritus.

RESULTS

Several barriers to treating pruritus emerged, including variable presentation, objective measurement of itch, and identifying therapeutic targets. Itch associated with autoimmune conditions, connective tissue diseases, genodermatoses, cutaneous T-cell lymphoma, and pruritus of unknown origin were among the etiologies with the greatest unmet needs.

CONCLUSION

Treating pruritus poses many challenges and there are many itchy conditions that have no yet been addressed. There is an urgent need for large-scale controlled studies to investigate potential targets for these conditions and novel therapies.

Pretibial Pruritic Papular Dermatitis: A Case Report and Emphasis on Effective Treatment with Pentoxifylline

Pretibial pruritic papular dermatitis (PPPD) is a distinctive skin disorder in response to persistent pretibial manipulation. Clinically, it manifests as multiple discrete, pruritic, flesh-colored-to-erythematous papules and plaques confined to the pretibial area. The histological hallmark of PPPD comprises irregular epidermal psoriasiform hyperplasia with parakeratosis and spongiosis, dermal fibrosis, and lymphohistiocytic infiltration. Due to its rarity and underrecognition, the prevalence and standard treatment of the disease have yet to be well elucidated. Here, we present a case of PPPD in a 60-year-old female presenting with numerous pruritic, erythematous-to-brownish papules and plaques on bilateral pretibial areas for 1.5 years. The lesions were significantly improved after 1 month of additional treatment with oral pentoxifylline. In this report, we aim to raise awareness in recognizing PPPD since it manifests unique clinical, dermoscopic, and histological features, representing pretibial skin's response to chronic rubbing. In addition, we proposed a novel effective therapy for the disease using pentoxifylline.

Primary Localized Cutaneous Amyloidosis: A Retrospective Study of an Uncommon Skin Disease in the Largest Tertiary Care Center in Switzerland

BACKGROUND

Primary localized cutaneous amyloidosis (PLCA) is defined by the deposition of amyloid protein in the skin without systemic involvement. There are four subtypes of PLCA: lichen amyloidosis (LA), macular amyloidosis (MA), biphasic amyloidosis (BA), and nodular amyloidosis (NA). PLCA occurs most frequently in Latin Americans and Asians. Treatment is not standardized.

OBJECTIVES

To identify subtypes, demographic and clinical features and treatment efficacy in patients with histopathologically confirmed PLCA.

MATERIALS AND METHODS

Data of PLCA patients were extracted from the electronic hospital database and included if diagnosis of PLCA was histopathologically confirmed and if sufficient information regarding treatment and follow-up was available. The evaluation of the treatment efficacy was based on a novel score to assess the reduction of itch and skin lesions.

RESULTS

In this retrospective, monocentric study, 37 cases of PLCA diagnosed between 2000 and 2020 were included (21 females) with a mean age of 52 years. LA was the most frequent subtype found in 21 patients (56.8%), followed by MA in 10 patients (28%) and BA in 6 patients (16.2%). No cases of NA were included. 22 patients (59.4%) had skin phototype II or III. Regarding treatment, a combination of UVA1 phototherapy with high-potency topical corticosteroids seemed to show the highest efficacy with complete clearance of symptoms in 4 patients (10.8%). A substantial improvement of symptoms was found in 5 patients (12.7%) treated with high-potency topical corticosteroids alone or in combination either with UVA1 or bath PUVA or monotherapy with UVA1 phototherapy or capsaicin (0.075%) cream. Low-/medium-potency topical corticosteroids alone or in combination with UVBnb (311 nm) phototherapy showed a lower efficacy.

CONCLUSION

Our data show that PCLA is a rare disease in central Europe but can also be expected in a predominantly Caucasian population. The best treatment response was achieved with a combination of UVA1 phototherapy and high-potency topical corticosteroids.

Primary Localized Cutaneous Amyloidosis of Keratinocyte Origin: An Update with Emphasis on Atypical Clinical Variants

Amyloid is a protein derived from at least 20 different substances. Once misfolded, it results in a group of cutaneous and systemic conditions. Primary localized cutaneous amyloidosis of keratinocyte origin is a very common subtype that can manifest either as lichen or macular amyloidosis, lacking systemic involvement. Lichen amyloidosis often presents as multiple hyperpigmented papules on the lower extremities whereas macular amyloidosis is classically characterized by dark brown rippled macules on the interscapular area. Review of the literature reveals that in addition to the classical presentation of primary localized cutaneous amyloidosis there exists a plethora of various manifestations that can be grouped into either geographic or morphologic categories. This review provides clinicians with the intimate knowledge of these presentations and summarizes the available treatment modalities.

Efficacy of topical dimethyl sulfoxide (DMSO) 50% solution vs tretinoin 0.5% cream in treatment of patients with primary macular amyloidosis: A split-side single-blinded randomized clinical trial

Primary localized cutaneous amyloidosis (PLCA) is a recalcitrant sporadic dermatological condition and most treatments have failed so far. We studied the efficacy of topical dimethyl sulfoxide (DMSO) 50% solution in comparison with tretinoin 0.5% cream in treatment of macular amyloidosis. In this split-side within-person single-blinded randomized clinical trial, 18 patients with bilateral macular amyloidosis received topical DMSO 50% solution and tretinoin 0.5% cream either on their right or the left side. The colorimetry, pruritus scoring, and photography were done. A significant pigmentation decline per each follow-up was observed in DMSO group compared to the tretinoin group (tretinoin: -1.31 vs DMSO: -7.34; difference in slopes: -6.03 [95% confidence interval: -12.06 to -0.01], P_Interaction = .049). An insignificant diminution trend in pigmentation was observed for both treatments (P_tretinoin = .672, P_DMSO = .092). Also, both treatments relived itchiness, but DMSO completely dispatched itchiness from the first follow-up (P = .003 for tretinoin and <.0001 for DMSO). In conclusion, our results showed DMSO and tretinoin cream have the positive effect on the both pigmentation and itchiness in PLCA. DMSO may be more beneficial than tretinoin, since DMSO was significantly better in reducing itchiness. More investigations are warranted to provide sufficient evidence.

Primary Localized Cutaneous Amyloidosis: A Systematic Treatment Review

BACKGROUND

Primary localized cutaneous amyloidosis (PLCA) is characterized by extracellular deposition of heterogenic amyloid proteins in the skin without systemic involvement. Lichen amyloidosis, macular amyloidosis, and (primary localized cutaneous) nodular amyloidosis are different subtypes of PLCA.

OBJECTIVE

The aim of this study was to review the current reported treatment options for PLCA.

METHODS

This systematic review was based on a search in the PubMed database for English and German articles from 1985 to 2016.

RESULTS

Reports on the treatment of PLCA were limited predominantly to case reports or small case series. There were a few clinical trials but these lacked control groups. A variety of treatment options for PLCA were reported including retinoids, corticosteroids, cyclophosphamide, cyclosporine, amitriptyline, colchicine, cepharanthin, tacrolimus, dimethyl sulfoxide, vitamin D₃ analogs, capsaicin, menthol, hydrocolloid dressings, surgical modalities, laser treatment, and phototherapy.

CONCLUSION

No definitive recommendation of preferable treatment procedures can be made based on the analyzed literature. Randomized controlled trials are needed to offer patients an evidence-based therapy with high-quality standardized treatment regimens for PLCA.

Cutaneous deposits

: The cutaneous deposition disorders are a group of unrelated conditions characterized by the accumulation of either endogenous or exogenous substances within the skin. These cutaneous deposits are substances that are not normal constituents of the skin and are laid down usually in the dermis, but also in the subcutis, in a variety of different circumstances. There are 5 broad categories of cutaneous deposits. The first group includes calcium salts, bone, and cartilage. The second category includes the hyaline deposits that may be seen in the dermis in several metabolic disorders, such as amyloidosis, gout, porphyria, and lipoid proteinosis. The third category includes various pigments, heavy metals, and complex drug pigments. The fourth category, cutaneous implants, includes substances that are inserted into the skin for cosmetic purposes. The fifth category includes miscellaneous substances, such as oxalate crystals and fiberglass. In this article, the authors review the clinicopathologic characteristics of cutaneous deposition diseases, classify the different types of cutaneous deposits, and identify all the histopathologic features that may assist in diagnosing the origin of a cutaneous deposit.

Thalidomide improves clinical symptoms of primary cutaneous amyloidosis: report of familiar and sporadic cases

Primary cutaneous amyloidosis (PCA), either familial or sporadic, poses a therapeutic challenge. We conducted an open trial using thalidomide to treat three cases of familial and three cases of sporadic PCA, at initial dose of 100 mg/day. Dosage adjustment was made according to improvement of symptoms or patient's own choice. All except one sporadic case experienced moderate to significant relief on the symptoms of itching, over an observational period of 8 weeks by visual analog score (from 8.08 ± 0.88 to 1.60 ± 0.68, on average) as well as clinical amelioration of symptoms. Side effects included fatigue, drowsiness, numbness, and facial and leg edema in some of the patients. From the present observation, it seems that thalidomide is a promising drug to treat PCA.

Cutaneous amyloidosis: a concept review

Concepts and semantics are crucial for good communication between clinicians and pathologists. Amyloidosis was described more than 150 years ago. Therefore, the terminology related to it is abundant, varied, and sometimes complex. In this report, we intend to discuss several terms related to the disease, with special emphasis on cutaneous amyloidosis. We present a review, from Virchow to present, of the concepts related to amyloidosis: its nature, the classification of cutaneous forms of the disease, and the techniques used in its diagnosis.

Case of primary localized cutaneous amyloidosis with protean clinical manifestations: lichen, poikiloderma-like, dyschromic and bullous variants

Primary localized cutaneous amyloidosis (PLCA) commonly presents as macular and lichen variants. We present a case of a 27-year-old Chinese woman with cutaneous features of the rarely reported poikiloderma-like, dyschromic and bullous forms of PLCA, and the commoner lichen variant. There were no syndromic associations or systemic involvement, and the various morphological subtypes occurred in isolation from one another. We review the clinical spectrum of PLCA, highlight its protean clinical manifestations in this patient, and discuss its postulated pathogenesis in relation to its histopathological features.

Transcutaneous electrical nerve stimulation for reduction of pruritus in macular amyloidosis and lichen simplex

Lichen simplex (LS) is characterized by circumscribed, lichenified, pruritic patches that may develop on any part of the body. Macular amyloidosis (MA) is the form of primary localized cutaneous amyloidosis. Transcutaneous electrical nerve stimulation (TENS) uses a pulsed electric current generated transcutaneously by a device to cause impulses to be carried along large-diameter afferent nerves. In this article, we report the effects of TENS on the Dermatology Life Quality Index (DLQI) measures and visual analogue scale (VAS) scores in patients with pruritus, in whom LS and MA were diagnosed. All patients with MA and six (75%) patients with LS had relief of their pruritus with TENS therapy. At week 2, there was a significant difference in median VAS scores between baseline in the group of LS (P = 0.007). At 4 weeks of therapy, statistically significant differences were observed compared with the baseline and week 2 in the median VAS scores in the group of MA (P < 0.001). There was also a statistically significant improvement in median DLQI total scores with respect to baseline, which was achieved as early as week 2 in patients with LS and MA who were on the TENS treatment (P = 0.006, P = 0.001, respectively).

A case of membranous lipodystrophy observed in lichen amyloidosis

Membranous lipodystrophy is characterized by the presence of microcysts lined by amorphous, eosinophilic material with an arabesque appearance. We experienced a case of a 72-year-old man who had dark brownish, pruritic papules on the arms, legs, and back. Histopathologic examination of a biopsied lesion showed homogeneous, eosinophilic material in the papillary dermis, as well as membranous lipodystrophy. We report a case of membranous lipodystrophy observed in lichen amyloidosis.

Pretibial dystrophic epidermolysis bullosa with localized cutaneous amyloidosis: coincidental or secondary amyloidosis?

Here, we describe the case of a patient with pretibial dystrophic epidermolysis bullosa (PDEB) with amyloid deposition. The patient was a 40-year-old Japanese woman who presented a blistering eruption in the pretibial area with flat violaceous-brown lichenoid papules. The histology of the blister revealed a subepidermal bulla with antibodies bound to basement membrane antigens on the blister roof by immunoflourescent mapping. Electron microscopy revealed a blister cleavage plane below the lamina densa. The histology of the lichenoid papules showed amyloid deposition in the papillary dermis. Because it was confined to just beneath the bulla base of the blister specimen, the amyloid deposition may have been derived from degenerated keratinocytes induced by damage to the epidermal-dermal junction due to blister formation in PDEB in this case. PDEB, in general, is often misdiagnosed as lichen amyloidosis; however, some PDEB cases could actually be associated with amyloid deposition.

Clinical and histopathological findings of 'psoriatic neurodermatitis' and of typical lichen simplex chronicus

BACKGROUND

We have seen several patients with itchy lichenified plaques located bilaterally on the elbows and/or knees and have named this condition 'psoriatic neurodermatitis' (PN).

OBJECTIVE

The purpose of this study was to compare clinical and histopathological characteristics of these patients to those of patients with typical lichen simplex chronicus (LSC).

METHODS

Nineteen patients with PN and 34 patients with typical LSC were included. Besides clinical dermatological evaluation, the prick test was carried out on 49 patients; the Phadiatop test on 40 patients; the patch test with European standard series on 47 patients; histopathological evaluation on 39 patients; and clinical psychiatric examination on 38 patients.

RESULTS

Almost exclusively, PN was seen in females and was located on the extremities. It caused more plaques than typical LSC did. In PN, the plaques were smaller, sharper, more keratotic and less excoriated, and had fewer lichenoid papules around them. Itching was usually more severe in the evening, while resting and in a hot environment in typical LSC, but not in PN. In plaques of PN, microabscesses in the horny layer, hypogranulosis, regular acanthosis and thinning of the suprapapillary plates were more frequent, and hyperpigmentation in the basal layer was less. In patients with PN, depressive disorder was found more frequently; and generalized anxiety disorder or psychosomatic characteristics, less. There were no significant differences in the results of prick, Phadiatop and patch tests between patients with PN and those with typical LSC.

CONCLUSION

In our opinion, it is most likely that the so-called PN is itchy psoriasis superimposed by LSC.

Successful treatment of lichen amyloidosis with combined bath PUVA photochemotherapy and oral acitretin

Lichen amyloidosis (LA) is a chronic, pruritic skin disorder characterized by brownish-grey papules on extensor surfaces of legs and rarely on the trunk. Thioflavin T-positive amyloid deposits are found in the papillary dermis of affected skin, which is the only organ involved. A variety of therapeutic regimens for lichen amyloidosis have been described; however, in many cases with only limited effect. We report on two patients with lichen amyloidosis with typical clinical symptoms not responding to local treatment. A combined regimen with bath psoralen ultraviolet A (PUVA) and oral acitretin was initiated, resulting in nearly complete resolution of the papules and impressive relief from the severe pruritus. The beneficial response has persisted for 8 months. The suggested combined therapy with bath PUVA photochemotherapy and oral acitretin represents an efficacious and practical treatment modality for lichen amyloidosis with long-lasting effects.

Primary cutaneous amyloidosis of the auricular concha: case report and review of published work

A 70-year-old Japanese female developed tiny papules on her bilateral ears 2 years previously. A histological study of a biopsy specimen revealed that amorphous materials were present in the widened dermal papillae. Because these materials were positive for both Congo red and Dylon, we diagnosed the lesion as primary cutaneous amyloidosis of the auricular concha. Immunohistochemically, the amyloid substance stained positively with 34betaE12 (cytokeratin 1/5/10/14), suggesting that it had an epidermal origin. Seven reported cases of this unique disorder were also reviewed.

Pretibial Pruritic Papular Dermatitis

We describe the clinico-pathologic features of 44 patients with a peculiar pretibial pruritic papular dermatitis (PPPD). Clinically, PPPD consists of discrete, roundish, extremely pruritic papules with a smooth surface caused by the delicate and persistent rubbing of pretibial skin. Histologically, PPPD showed minimal compact orthokeratosis, flattening of the rete ridges, a superficial and mid-dermal perivascular and interstitial infiltrate of lymphocytes, histiocytes, eosinophils and multinucleated fibroblasts, and thickened collagen bundles in haphazard array in the superficial dermis. The clinical picture of PPPD closely resembled that of lichen simplex chronicus/circumscribed neurodermatitis or lichen amyloidosus. Histologically, the absence of uneven psoriasiform epidermal hyperplasia, marked compact orthokeratosis, hypergranulosis, and coarse bundles of collagen arranged in vertical streaks in the papillary dermis distinguished PPPD from lichen simplex chronicus, whereas the lack of amyloid deposits in the dermal papillae differentiated PPPD from lichen amyloidosus. We suggest that PPPD is an unusual morphologic expression of gentle and chronic rubbing of pretibial skin with distinctive histopathologic features.

My approach to superficial inflammatory dermatoses

Superficial inflammatory dermatoses are very common and comprise a wide, complex variety of clinical conditions. Accurate histological diagnosis, although it can sometimes be difficult to establish, is essential for clinical management. Knowledge of the microanatomy of the skin is important to recognise the variable histological patterns of inflammatory skin diseases. This article reviews the non-vesiculobullous/pustular inflammatory superficial dermatoses based on the compartmental microanatomy of the skin.

Lichen amyloidosus treated by hydrocolloid dressings

We hereby report a case of lichen amyloidosus in a 69-year-old man unresponsive to various treatments. The patient was treated by occlusion with hydrocolloid dressings. Considerable subjective and objective improvement was observed with respect to the pruritus and cosmetic appearance. We suggest this convenient and efficacious treatment as first line therapy.

Co-existence of lichen amyloidosus and angiolymphoid hyperplasia with eosinophilia

Summary Angiolymphoid hyperplasia with eosinophilia (ALHE) is an uncommon benign vascular tumour. It presents with small, dull red papules or nodules usually on the ears and preauricular areas and only 20% of lesions are multiple. We report a case of multiple scattered lesions of ALHE in a patient who subsequently developed lichen amyloidosus. Cases of lichen amyloidosus in association with Kimura's disease have been reported previously, but there are no reports of lichen amyloidosus with ALHE. The coexistence of these two conditions implies that ALHE is an inflammatory disorder, as an inflammatory process resulting in basal layer damage is necessary for the occurrence of lichen amyloidosus.

Frequent association between MEN 2A and cutaneous lichen amyloidosis

OBJECTIVE

Multiple endocrine neoplasia type 2A (MEN 2A) and familial medullary thyroid carcinoma (FMTC) are genetic diseases due to activating mutations of the RET proto-oncogene. Affected patients develop medullary thyroid carcinoma (100%), in an isolated form (FMTC) or in association with phaeochromocytoma (30-50%), and primary hyperparathyroidism (10-20%) (MEN 2A). The presence of cutaneous lichen amyloidosis (CLA) has been anecdotally described in few families harbouring RET proto-oncogene mutation in codon 634. The aim of the study was to evaluate the incidence of CLA in MEN 2A/FMTC families.

PATIENTS AND DESIGN

Ten MEN 2A/FMTC families were studied and RET gene mutations identified in all. Complete dermatological assessment was carried out in each family member. Skin biopsy for histological studies was performed in patients with CLA.

RESULTS

Among 10 MEN 2A/FMTC families, the presence of CLA was found only in patients belonging to the three families with MEN 2A and RET mutation in codon 634. Nine of 25 patients (36%) with codon 634 mutation presented CLA, though two of them did not show CLA skin lesions but the typical neurological pruritus in the upper back. In all patients, neurological pruritus was present since infancy as a precocious marker of the disorder. The dermatological study of patients with CLA skin lesions added further evidence that pruritus has a pivotal role in the development of CLA, the amyloid deposition being the consequence of repeated scratching. Light microscopy revealed orthokeratotic hyperkeratosis, with elongation of the rete ridges, rare intramalpighian apoptic keratinocytes and deposits of amorphous material in the superficial dermis. Examination under ultraviolet light showed thioflavin T-positive staining, confirming the presence of amyloid in the papillary dermis. The use of Capsaicin at the dilution of 0.025% had a mild efficacy on the cutaneous symptoms.

CONCLUSIONS

Among the members of the three families with MEN 2A and RET 634 mutation, the incidence of CLA was 36%, a figure similar to that reported in the literature for phaeochromocytoma (30-50%) and even higher than that for hyperparathyroidism (10-20%). The present data confirm that CLA is linked to codon 634 RET mutations and is a precocious marker of the disorder.

An unusual form of primary systemic amyloidosis: amyloid elastosis: report of a case treated by haematopoietic cell transplantation

Amyloid elastosis is a rare variant of primary systemic amyloidosis characterized by amyloid deposited around elastic fibres. Only two cases, with pseudoxanthoma elasticum-like features and fatal outcome, have been reported. A 56-year-old woman presented with polyneuropathy and a diffuse plane xanthoma-like eruption. Light and electron microscopy studies revealed deposits of amyloid L encasing either normal-looking or short, fragmented elastic fibres in the dermis in a pattern characteristic of amyloid elastosis. The patient had medullary plasmocytosis with lambda light chain restricted expression and underwent autologous stem cell transplantation, which resulted in progressive regression of mucocutaneous signs and stabilization of the polyneuropathy. Our case extends the spectrum of clinical and histopathological presentations of amyloid elastosis. Haematopoietic cell transplantation might improve outcome in patients with multisystem disease.

Lack of effect of dimethylsulphoxide in cutaneous amyloidosis

OBJECTIVE

To evaluate dimethylsulphoxide (DMSO) as a topical therapeutic agent for the treatment of two major variants of primary, localized, cutaneous amyloidosis -- macular amyloidosis (MA) and papular/lichen amyloidosis (LA) -- using a monocentric, open, prospective trial.

METHODS

A total of 25 patients with histopathologically proven cutaneous amyloidosis - MA, LA and BA (biphasic amyloidosis) (13 MA, seven LA, five BA) were requested to undertake a once daily application of either 50% or 100% DMSO for 12 weeks. Progress was regularly assessed with a scoring system for pruritus, pigmentation and papules.

RESULTS

In 17 (68%) cases, the scores for pruritus decreased but never completely disappeared in any of the patients. Lightening of the pigmentation was noted in only six (24%) cases and the scores for the papules were decreased in only two out of 12 (16.6%) patients. Post-treatment skin biopsies did not reveal a reduction/disappearance of the amyloid deposits. In the follow-up period, the relapse rate was 100%.

CONCLUSION

DMSO does not have an anti-pruritic effect or amyloid-dissolving properties. As the results are partial and transient, it is concluded that DMSO is not a satisfactory treatment for cutaneous amyloidosis.

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.

Familial primary cutaneous amyloidosis in a South African family

Four members of a white South African family, spanning four generations were diagnosed as suffering from familial primary lichen amyloidosis. All showed similar clinical features which included scaling papules on the lower legs and arms, and a pebbled, lichenified appearance of the skin on the back. The diagnosis was confirmed by light and electron microscopy. This is the eleventh report of familial primary cutaneous amyloidosis and the first in South Africa.