Thermosensitive lichen amyloidosis

A Case Report of Generalized Non-pruritic Lichen Amyloidosis

We evaluate the rare case of a patient who presented with generalized, non-pruritic lichen amyloidosis. There are three reported cases of generalized and non-pruritic lichen amyloidosis. The lichen amyloidosis subtype of primary localized cutaneous amyloidosis is characterized by keratinocyte-derived amyloid deposition in the papillary dermis, classically presenting as pruritic, hyperpigmented macules coalescing into plaques on the lower extremities. While the pathogenesis is likely multifactorial, chronic scratching has been proposed as an inciting factor. The patient's type of lichen amyloidosis challenges the proposed etiology of chronic scratching leading to amyloid deposition.

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.

Automated assessment and tracking of human body thermal variations using unsupervised clustering

The presented approach addresses a review of the overheating that occurs during radiological examinations, such as magnetic resonance imaging, and a series of thermal experiments to determine a thermally suitable fabric material that should be used for radiological gowns. Moreover, an automatic system for detecting and tracking of the thermal fluctuation is presented. It applies hue-saturated-value-based kernelled k-means clustering, which initializes and controls the points that lie on the region-of-interest (ROI) boundary. Afterward, a particle filter tracks the targeted ROI during the video sequence independently of previous locations of overheating spots. The proposed approach was tested during experiments and under conditions very similar to those used during real radiology exams. Six subjects have voluntarily participated in these experiments. To simulate the hot spots occurring during radiology, a controllable heat source was utilized near the subject's body. The results indicate promising accuracy for the proposed approach to track hot spots. Some approximations were used regarding the transmittance of the atmosphere, and emissivity of the fabric could be neglected because of the independence of the proposed approach for these parameters. The approach can track the heating spots continuously and correctly, even for moving subjects, and provides considerable robustness against motion artifact, which occurs during most medical radiology procedures.

New insight into mechanisms of pruritus from molecular studies on familial primary localized cutaneous amyloidosis

Macular and lichen amyloidosis are common variants of primary localized cutaneous amyloidosis (PLCA) in which clinical features of pruritus and skin scratching are associated with histological findings of deposits of amyloid staining on keratinous debris in the papillary dermis. Most cases are sporadic, but an autosomal dominant family history may be present in up to 10% of cases, consistent with a genetic predisposition in some individuals. Familial PLCA has been mapped to a locus on 5p13.1-q11.2 and in 2008 pathogenic heterozygous missense mutations were identified in the OSMR gene, which encodes oncostatin M receptor beta (OSMRbeta), an interleukin (IL)-6 family cytokine receptor. OSMRbeta is expressed in various cell types, including keratinocytes, cutaneous nerves and nociceptive neurones in dorsal root ganglia; its ligands are oncostatin M and IL-31. All pathogenic mutations are clustered in the fibronectin-III repeat domains of the extracellular part of OSMRbeta, sites that are critical for receptor dimerization (with either gp130 or IL-31RA), and lead to defective signalling through Janus kinase-signal transducers and activators of transcription, extracellular signal-regulated protein kinase 1/2 and phosphoinositide 3 kinase/Akt pathways. Elucidating the molecular pathology of familial PLCA provides new insight into mechanisms of pruritus in human skin, findings that may have relevance to developing novel treatments for skin itching. This review provides a clinicopathological and molecular update on familial PLCA.