Current topical and systemic therapies for itch.

Itch is a common distressing symptom which may be caused by multifactorial aetiologies including inflammatory skin diseases, systemic diseases, neuropathic conditions and psychogenic disorders. Itch is a term used synonymously with pruritus and is defined as acute if it lasts less than 6 weeks or chronic if it persists for more than 6 weeks. It can have the same impact on the quality of life as chronic pain and shares many of the same pathophysiological pathways.

Pathology and classification of urticaria.

Chronic urticaria is defined as daily or almost daily urticaria for more than 6 weeks. Chronic urticaria is normally subdivided into physical urticaria (wheals evoked by a physical stimulus such as pressure friction or cold contact) and spontaneous urticaria. A patient with a history of less than 6 weeks is traditionally designated as having acute urticaria.

Detection of refractive index changes in individual living cells by means of surface plasmon resonance imaging.

Real time imaging of living cell activation is an increasing demand in disciplines of life science and medicine. We previously reported that surface plasmon resonance (SPR) sensors detect large changes of refractive index with living cells, such as mast cells, keratinocyte, human basophils and B-cells activated by biological stimuli. However, conventional SPR sensors detect only an average change of refractive index with thousands of cells at detectable area on a sensor chip.

Pathogenesis and treatment of pruritus.

Classification of itch into four categories-pruritoceptive, neurogenic, neuropathic, and psychogenic-has proven to be of utility to clinicians and investigators. Itch is recognized to be transmitted by dedicated afferent neurons, and a matrix of cerebral cortical loci involved in perception and the desire to scratch has been recognized. This highlights the multidimensional nature of the itch sensation.

Chronic urticaria: recent advances.

Chronic urticaria is an umbrella term, which encompasses physical urticarias, chronic "idiopathic" urticaria and urticarial vasculitis. It is important to recognize patients with physical urticarias as the investigation and treatment differs in important ways from patients with idiopathic chronic urticaria or urticarial vasculitis. Although relatively uncommon, urticarial vasculitis is an important diagnosis to make and requires histological confirmation by biopsy.

Recent advances in pathophysiology and current management of itch.

The neurophysiology of itch, the dominant symptom of skin disease, has previously received scant attention. Recent advances in the neurophysiology and molecular basis of itch include the use of microneurography to demonstrate the existence of a subset of itch-dedicated afferent C neurons distinct from neurons which transmit pain; use of functional positron emission tomography (PET) and magnetic resonance imaging (MRI) of the brain to reveal an itch-specific activation matrix, and new evidence of a functional "dialogue" between C neuron terminals and dermal mast cells in which recently described proteinase-activated receptor type 2 (PAR2) and transient receptor potential vanilloid 1 (TRPV1) receptors, proteases and endovanilloids play a major role. As a necessary prerequisite to diagnosis and management, a pathophysiologically based classification of itch is proposed.

Cutaneous mast cell receptors.

Two types of mast cells, MC(T) and MC(TC), exist in humans. MC(T) and MC(TC) are different in their granular neutral proteases, tissue localizations, and functions. This article describes the differences between the cutaneous mast cell receptors.

Clinical classification of itch: a position paper of the International Forum for the Study of Itch.

Chronic itch is a common and distressing symptom that arises from a variety of skin conditions and systemic diseases. Despite this, there is no clinically based classification of pruritic diseases to assist in the diagnosis and cost-effective medical care of patients with pruritus. The proposed classification focuses on clinical signs and distinguishes between diseases with and without primary or secondary skin lesions.

Itch in systemic disease: therapeutic options.

A new pathophysiologically based classification of itch is proposed, which should help the clinician adopt a rational approach to diagnosis and management of generalized itch. Focusing on neurogenic itch (itch without visible rash), common causes are reviewed and guidelines for laboratory and radiologic investigation are proposed. A stepwise approach to the management of generalized itch resulting from systemic disease is recommended.

Angioedema.

Unlabelled: Although first described more than 130 years ago, the pathophysiology, origin, and management of the several types of angioedema are poorly understood by most dermatologists. Although clinically similar, angioedema can be caused by either mast cell degranulation or activation of kinin formation. In the former category, allergic and nonsteroidal anti-inflammatory drug-induced angioedema are frequently accompanied by urticaria.

Antihistamines in dermatology.

Along with antibiotics, antihistamines are the most widely used systemic drugs in dermatology. This is attributable to the major role played by histamine in common diseases such as urticaria and atopic eczema. Of the currently recognised four subtypes of G protein-coupled histamine receptors, only the H1 and H2 subtypes have been positively identified in human skin.

Itch: more than skin deep.

Recent research in neurophysiology of itch has indicated the existence of itch-dedicated nociceptor neurones. The perception of itch is regulated by tonically inhibitory descending neuronal pathways and nociceptor spinal neuronal circuits. There is at present no convincing evidence of an 'itch centre' in the brain.

N95 acne.

Two women, aged 27 and 45 years, presented to the Dermatology Outpatient Clinic with acne vulgaris. Both had nodular acne in a similar distribution over the cheeks, chin, and perioral areas (Fig. 1).

Chronic idiopathic urticaria.

Purpose Of Review: Chronic idiopathic urticaria has long been a demoralizing disease, baffling allergists and dermatologists alike, to the detriment of the patient. Recent findings, however, have shed light on causation in many, though not all, of these patients. The purpose of this review is to bring the reader up to date on the current position regarding aetiology and pathogenesis and the strength of the evidence.

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.

Classification of anti-FcepsilonRI and anti-IgE autoantibodies in chronic idiopathic urticaria and correlation with disease severity.

Background: Circulating autoantibodies against FcepsilonRI, IgE, or both occur in approximately one third of patients with chronic idiopathic urticaria (CIU), but not all autoantibodies initiate histamine release.

Objective: We sought to classify patients with CIU into subsets on the basis of serum bioactivity and immunoreactivity and to examine the relationship between newly defined subtype and disease severity.

Methods: Sera from patients with CIU (n = 78), dermog-raphism (n = 15), and cholinergic urticaria (n = 10) and sera from healthy subjects (n = 39) were analyzed by means of Western blot analysis for anti-FcepsilonRI autoantibodies and for histamine release from basophils and dermal mast cells.

Antihistamines in urticaria and angioedema.

H1-antihistamines are the cornerstone of symptomatic treatment in acute and chronic urticaria, in which they not only relieve itching, but also reduce the number, size, and duration of urticarial lesions. Relief of whealing, flaring, and erythema may be incomplete as the vascular effects of histamine are mediated to its action at H2-receptors as well as at H1-receptors, and other vasoactive substances may also be involved. In randomized, prospective, placebo-controlled, double-blind studies, the new low-sedating H1-antihistamines have been found to be effective and safe in urticaria.

Drug-induced urticaria and angioedema: pathomechanisms and frequencies in a developing country and in developed countries.

A careful drug history should be obtained from all patients with acute or chronic urticaria/angioedema, especially in the elderly. Although strictly comparable data are lacking, drug-induced urticaria appears to be more common in developed countries than in Malaysia, at least in a Hospital setting. Culprit drugs include antibiotics, analgesics and contrast media.