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Biomedical subjects

Gil Yosipovitch

Publications and source records attributed to Gil Yosipovitch.

12 recordsLinked to original sources

Itch.

Itch is a common skin sensation, with substantial effects on behaviour. Neurophysiological research has permitted accurate definition of neural pathways of itch, and has confirmed the distinctiveness of itch pathways in comparison with pain. A clinical classification of itch, based on such improved understanding, describes the difference between peripheral (pruritoceptive) and central (neurogenic or neuropathic) itch. New specific and sensitive investigational methods in people and animals enable us to better understand this bothersome symptom, and have important clinical implications. We describe the clinical classification of itch, new findings on neuropathophysiology of itch, methods for assessment, and improved treatments.

Animals↗

Granular parakeratosis: a case report and literature review.

BACKGROUND: Granular parakeratosis is suspected to result from an error in epidermal differentiation, leading to variably pruritic, hyperpigmented-to-erythematous patches and plaques. Characteristic histopathologic features include a thickened stratum corneum, compact parakeratosis with retention of keratohyalin granules, vascular proliferation, and ectasia. The pathogenesis of this entity is uncertain. METHODS: We present a case of axillary granular parakeratosis and review the literature. RESULTS: The lesion showed a thickened stratum corneum with compact parakeratosis, slight epidermal hyperplasia, and a sparse perivascular lymphohistiocytic infiltrate. Keratohyalin granules were diffusely present within the parakeratotic stratum corneum, and the retained granular layer showed focal vacuolization. CONCLUSIONS: Granular parakeratosis is a rare form of parakeratosis most often seen in the axilla, although other intertriginous areas may be affected. Unique histopathologic findings allow for a specific diagnosis to be made. Although an irritant contact reaction appears causative, mechanical irritation may also play a role in inducing these skin changes.

Administration, Topical↗

Epidermolytic hyperkeratosis and epidermolysis bullosa simplex caused by frameshift mutations altering the v2 tail domains of keratin 1 and keratin 5.

The cytoskeleton of epithelial cells is formed by heteropolymeric keratin proteins characterized by a central alpha-helical rod flanked by nonhelical head and tail domains of variable sequence. Most mutations described in 18 distinct keratins disrupt highly conserved regions at the boundaries of the rod, which have been recognized as zones of overlap during keratin alignment and assembly into intermediate filaments. We recently reported the first mutation located in a keratin tail domain (V2) in ichthyosis hystrix Curth-Macklin. In this study, we report two novel frameshift mutations that are predicted to alter the tail of keratin 1 or keratin 5, leading to an atypical form of epidermolytic hyperkeratosis and a mild form of epidermolysis bullosa simplex, respectively. Mutation analysis of the patient with epidermolytic hyperkeratosis revealed a de novo heterozygous nucleotide insertion (1752insG) in exon 9 of KRT1, predicted to result in an aberrant 69 residue keratin 1 tail. In the patient with mild epidermolysis bullosa simplex, we identified a single nucleotide deletion (1635delG) in exon 9 of KRT5 leading to frameshift and translation of an abnormal V2 domain, 35 amino acids longer than the native keratin 5 tail. Our results, together with previous observations, establish the existence of a subgroup of keratin disorders due to frameshift mutations altering the keratin tail domains that are characterized by phenotypic heterogeneity.

Adolescent↗

Hemorrhagic bullae after cryosurgery in a patient with hemophilia A.

BACKGROUND: A case of hemorrhagic bullae and blisters on the hand of a patient with hemophilia A after cryosurgery for verruca vulgaris is reported. OBJECTIVE: To discuss a hemorrhagic complication in a patient with hemophilia A after cutaneous cryosurgery. METHODS: This is an observatory case report. RESULTS: Even minimal cryosurgery can induce hemorrhagic bullae in patients with hemophilia A. CONCLUSION: The risks and benefits of cryosurgery should be weighed carefully in patients with bleeding disorders such as hemophilia.

Blister↗

Suggested guidelines for screening and management of tuberculosis in patients taking oral glucocorticoids--an important but often neglected issue.

One third of the world's population is infected with tuberculosis and its incidence is increasing. Systemic glucocorticoids are the mainstay of immunosuppressive therapy for immunobullous diseases and collagen vascular diseases in dermatology. Patients who are given prolonged glucocorticoid therapy may be at risk for both the acquisition of primary tuberculosis and the reactivation of nonactive tuberculosis. The purpose of this article is to highlight the importance of screening for tuberculosis and its management in this group of patients, as there are no published guidelines in the dermatology literature on this subject. We summarize the methods used for tuberculosis screening, give an account of treatment regimens for the various types of tuberculosis infection, and suggest a practical approach to screening and management of tuberculosis in patients receiving long-term glucocorticoid therapy.

Comorbidity↗

Photo recall phenomenon: an adverse reaction to taxanes.

Taxanes are a new group of chemotherapeutic agents, which share some pharmacological characteristics with methotrexate. Methotrexate has previously been reported to cause a photo recall phenomenon which develops 3-5 days after UV radiation, suggesting that taxanes can induce a similar reaction. This should be added to the list of cutaneous side-effects of this class of chemotherapeutic agents. We report a case of photo recall phenomenon in a 55-year-old Chinese woman with metastatic breast cancer who was undergoing chemotherapy with taxanes.

Antimetabolites, Antineoplastic↗

Itch associated with skin disease: advances in pathophysiology and emerging therapies.

Itch, also known as pruritus, is the major symptom in skin diseases with a variety of etiologies and pathophysiologies. Significant progress has been achieved in understanding the pathophysiology of itch in the last 5 years. Neurophysiological experiments in humans and animals have revealed that itch is carried by specific C nerve fibers. Recent studies have demonstrated that peripheral mediators other than histamine are involved in induction of itch. Mast cell tryptase seems to be an important mediator in itch by its activation of proteinase activated receptor 2 in the sensory nerves. Opioids have central and peripheral itch producing activity. Neuropeptides, such as substance P, induce itch by their effect on mast cells. Based upon our improved understanding of the neurophysiology of itch a clinical classification of itch has been proposed. The classification highlights differences between peripheral pruritoceptive itch, neuropathic itch (itch related to damage to afferent nerve fibers) and neurogenic itch (itch originating in the central nervous system without any evidence of nerve damage). Emerging therapies based on these findings include topical vanilloid receptor antagonists, topical antihistamines, and topical arachidonic acid inhibitors, as well as inhibitors of non-histamine inflammatory mediators, immunomodulators and strontium salts. Systemic therapies include thalidomide, opioid antagonists, phototherapy with narrow band UVB and experimental treatments with cutaneous field stimulation and vagal nerve stimulation. With the new information it seems we will be able to better help our dermatologic patients who have itch, however we are not closer to identifying a single agent specifically targetable to this symptom.

Adjuvants, Immunologic↗

Itch characteristics in Chinese patients with atopic dermatitis using a new questionnaire for the assessment of pruritus.

BACKGROUND: Although pruritus is the predominant and commonest feature of atopic dermatitis, its clinical characteristics have not been explored. OBJECTIVE: To characterize the clinical pattern and sensory and affective dimensions of the itch experience utilizing a comprehensive itch questionnaire. METHODS: A structured itch questionnaire based on the McGill pain questionnaire was given to 102 Chinese patients with known atopic dermatitis. RESULTS: There were 100 patients with atopic dermatitis who fully filled the questionnaire. In 87% of the patients pruritus appeared on a daily basis. It had a prolonged duration (mean duration 10.7 7.3 years). It involved all body areas mostly in the lower limbs (83%), flexures (76%), upper limbs (71%) and neck (65%). Itch intensity during its peak was nearly twice higher than the itch of a mosquito bite. Itching was most frequent at night (65%), and 84% of patients reported of difficulty falling asleep. Daily life activities which increased the severity of itch were sweat in 96%, dryness in 71%, stress in 71% and physical effort in 73%. The major factors which were found to reduce the intensity of pruritus included: bathing with cold water in 55% and cold ambient environment in 56%. Associated symptoms were heat sensation (51%), sweating (40%) and pain in the pruritic area (45%). The various anti-pruritic therapies had limited long-term effect. The pruritus was bothersome (52%) and a major distress to the patient. The affective score correlated to itch intensity during its peak (r = 0.4, P < 0.001). CONCLUSIONS: The study provided a detailed description of pruritus in atopic dermatitis with new data on affective and sensory dimensions and associated symptoms. The questionnaire was found to be a useful tool in characterization of itch.

Adolescent↗

Practical management of psoriasis in the elderly: epidemiology, clinical aspects, quality of life, patient education and treatment options.

Psoriasis in the elderly will constitute a significant challenge for the practising physician in this new millennium. Special considerations for the elderly include drug-induced or drug-aggravated psoriasis, especially for patients receiving polypharmacy or with recent worsening or poor response to conventional therapy. Other frequently encountered forms of psoriasis in the elderly include psoriatic arthritis and its complications, inverse psoriasis and potentially life-threatening complications such as erythrodermic or acute pustular psoriasis, where early recognition and systemic therapy is critical. Faced with an array of topical and systemic drug therapy options, it is of paramount importance that the physician remains focused on the holistic management of the patient, in order to achieve optimal compliance and benefit. This can be achieved through careful attention to quality-of-life issues, especially since many elderly patients may have other medical, social and economic comorbidities that can further negatively affect their overall quality of life. It is also essential that the severity of psoriasis be assessed on a more balanced, holistic scale that incorporates both physical and psychological parameters, such as the Salford Psoriasis Index. The patient and caregiver education should be multi-faceted, regularly conducted and practically orientated. Treatment goals should be kept simple and individualised for each patient, based on concomitant comorbidities, potential adverse effects, existing quality of life, self-care capability, drug history, caregiver situation, financial needs, feasibility for follow-up and patient's preferences. Topically applied medications, such as topical corticosteroids, salicylic acid, tar and dithranol preparations, calcipotriol and tazarotene, are the favoured first-line therapeutic options in the elderly. Narrowband ultraviolet B phototherapy is also well established as a standard therapy for psoriasis. Systemic therapy with agents such as methotrexate, acitretin and cyclosporin should be judiciously reserved for severe, extensive cases in view of their lower therapeutic index in the elderly. The ambulatory psoriasis treatment centre is an integral part of the overall cost-effective management of patients with psoriasis that can function as a 'one-stop' treatment and resource centre for the elderly patient.

Administration, Topical↗

Palmar-plantar keratoderma of Unna Thost associated with atopic dermatitis: an underrecognized entity?

We report six cases of palmar-plantar keratoderma of Unna Thost (PPKUT) associated with atopic dermatitis. All had typical features of PPKUT with diffuse, yellowish thickening on the palms and soles with a well-defined erythematous rim of demarcation on the sides associated with palmar-plantar hyperhidrosis. The changes were obvious since birth or arose during early life, and were persistent. We believe that the association between the two disorders is not coincidental but an underrecognized entity that may shed light on the underlying pathogenesis of these two conditions.

Adult↗