Patch testing in prurigo nodularis

Contact dermatitis: a practice parameter-update 2015

This parameter was developed by the Joint Task Force on Practice Parameters, which represents the American Academy of Allergy, Asthma & Immunology (AAAAI); the American College of Allergy, Asthma & Immunology (ACAAI); and the Joint Council of Allergy, Asthma & Immunology. The AAAAI and the ACAAI have jointly accepted responsibility for establishing "Contact Dermatitis: A Practice Parameter-Update 2015." This is a complete and comprehensive document at the current time. The medical environment is changing and not all recommendations will be appropriate or applicable to all patients. Because this document incorporated the efforts of many participants, no single individual, including members serving on the Joint Task Force, are authorized to provide an official AAAAI or ACAAI interpretation of these practice parameters. Any request for information or interpretation of this practice parameter by the AAAAI or ACAAI should be directed to the Executive Offices of the AAAAI, the ACAAI, and the Joint Council of Allergy, Asthma & Immunology. These parameters are not designed for use by the pharmaceutical industry in drug development or promotion. Previously published practice parameters of the Joint Task Force on Practice Parameters for Allergy & Immunology are available at http://www.JCAAI.org or http://www.allergyparameters.org.

Prurigo nodularis: A review

Prurigo nodularis is a chronic condition characterized by a papulonodular pruriginous eruption of unknown aetiology. This condition is a difficult disease to treat and causes frustration to both the patient and the treating doctor. A variety of systemic conditions have been reported to be associated with prurigo nodularis. The mechanism by which these disorders may trigger prurigo nodularis is unknown. Nerve growth factor has been implicated in the pathogenesis of prurigo nodularis. Calcitonin gene-related peptide and substance P immunoreactive nerves are markedly increased in prurigo nodularis when compared with normal skin. These neuropeptides may mediate the cutaneous neurogenic inflammation and pruritus in prurigo nodularis. Topical or intralesional glucocorticoids are the treatment of choice. Other topical treatments such as topical vitamin D3, and topical capsaicin have also been reported to be effective. Oral treatments such as cyclosporin and thalidomide have been shown to improve both appearance of the skin and pruritus. We review the clinical features, associations, pathology, pathogenesis and treatment of prurigo nodularis.

Prurigo: diagnosis and management

Prurigo is a condition of nodular cutaneous lesions that itch (pruire) intensely. Although the acute form can be caused by insect stings, most of the subacute and chronic forms appear to be idiopathic. Toxic agents deposited in the skin by exogenous factors such as parasites, bacteria, or topically or orally administered drugs can induce itch. In susceptible individuals, physical mechanisms such as UV light can induce changes in epidermal innervation that result both in itch generally and in prurigo lesions. Prurigo is sometimes associated with atopy, pregnancy, internal diseases, malabsorption, or malignancy. Some forms of prurigo may be secondary to scratching. Emotional factors can also influence the perception of itch and induce prurigo by provoking scratching. These are the various specialized forms of prurigo, and there are certain others, such as prurigo pigmentosa, that have some ethnic preference. Topical treatments by corticosteroids, coal tar, bath photochemotherapy, UVB, cryotherapy, or capsaicin, as well as systemic regimens involving use of psoralen + UVA (PUVA), erythromycin, arotinoid acid, cyclosporine, chloroquine, dapsone, minocycline, naltrexone, azathioprine or thalidomide are used for the treatment of this condition. Psychotherapeutic agents to treat problems of mood that deteriorate prurigo are also prescribed. Combined sequential treatments for generalized, therapy-resistant cases need to be tailored to the exacerbations that occur and to provide maintenance treatment in order to enable the patient to withstand the intolerable itch.

Prurigo nodularis of Hyde: an update

Prurigo nodularis of Hyde is an unusual disorder of unknown aetiology characterized by extremely pruritic nodules with well defined clinical and histopathological aspects. The literature on this disease is reviewed, focusing on the historical background, aetiology, pathogenesis, histopathology and ultrastructure, clinical aspects, differential diagnosis and therapeutic alternatives.