Cutaneous melanin pigment plays a critical role in camouflage, mimicry, social communication, and protection against harmful effects of solar radiation. Melanogenesis is under complex regulatory control by multiple agents interacting via pathways activated by receptor-dependent and -independent mechanisms, in hormonal, auto-, para-, or intracrine fashion. Because of the multidirectional nature and heterogeneous character of the melanogenesis modifying agents, its controlling factors are not organized into simple linear sequences, but they interphase instead in a multidimensional network, with extensive functional overlapping with connections arranged both in series and in parallel. The most important positive regulator of melanogenesis is the MC1 receptor with its ligands melanocortins and ACTH, whereas among the negative regulators agouti protein stands out, determining intensity of melanogenesis and also the type of melanin synthesized. Within the context of the skin as a stress organ, melanogenic activity serves as a unique molecular sensor and transducer of noxious signals and as regulator of local homeostasis. In keeping with these multiple roles, melanogenesis is controlled by a highly structured system, active since early embryogenesis and capable of superselective functional regulation that may reach down to the cellular level represented by single melanocytes. Indeed, the significance of melanogenesis extends beyond the mere assignment of a color trait.

https://www.physiology.org/doi/pdf/10.1152/physrev.00044.2003

Melanin Pigmentation in Mammalian Skin and Its Hormonal Regulation

Latex surgical gloves may cause contact urticaria and serious allergic reactions in sensitized persons, but the frequency of this allergy is not known. In the present study, 512 hospital employees were screened with a latex-glove scratch-chamber test; 23 (4.5%) were suspected and 15 (2.9%) were proven allergic with latex prick and use tests. All of them were doctors and nurses, and 12 had had contact urticaria but no serious symptoms. They could continue their routine work using cotton or vinyl undergloves or special latex surgical gloves. Atopy, hand eczema and surgical work seemed to be predisposing factors. In operating units, 7.4% of the doctors and 5.6% of the nurses were allergic; the frequency was lower in non-operating units and among laboratory personnel. The high frequency of latex glove allergy, especially in operating units, focuses attention on the quality of surgical latex gloves.

Incidence of immediate allergy to latex gloves in hospital personnel.

These parameters were developed by the Joint Task Force on Practice Parameters (JTFPP), representing 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 ACAAI have jointly accepted responsibility for establishing "The diagnosis and management of acute and chronic urticaria: 2014 update." This is a complete and comprehensive document at the current time. The medical environment is a changing environment, and not all recommendations will be appropriate for all patients. Because this document incorporated the efforts of many participants, no single individual, including those who served on the JTFPP, is authorized to provide an official AAAAI or ACAAI interpretation of these practice parameters. Any request for information about or an interpretation of these practice parameters 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. The JTFPP understands that the cost of diagnostic tests and therapeutic agents is an important concern that might appropriately influence the work-up and treatment chosen for a given patient. The JTFPP recognizes that the emphasis of our primary recommendations regarding a medication might vary, for example, depending on third-party payer issues and product patent expiration dates. However, because a given test or agent's cost is so widely variable and there is a paucity of pharmacoeconomic data, the JTFPP generally does not consider cost when formulating practice parameter recommendations. In extraordinary circumstances, when the cost/benefit ratio of an intervention is prohibitive, as supported by pharmacoeconomic data, commentary might be provided. These parameters are not designed for use by pharmaceutical companies in drug promotion. The JTFPP is committed to ensuring that the practice parameters are based on the best scientific evidence that is free of commercial bias. To this end, the parameter development process includes multiple layers of rigorous review. These layers include the workgroup convened to draft the parameter, the task force reviewers, and peer review by members of each sponsoring society. Although the task force has the final responsibility for the content of the documents submitted for publication, each reviewer comment will be discussed, and reviewers will receive written responses to comments, when appropriate. To preserve the greatest transparency regarding potential conflicts of interest, all members of the JTFPP and the practice parameter workgroups will complete a standard potential conflict of interest disclosure form, which will be available for external review by the sponsoring organization and any other interested individual. In addition, before confirming the selection of a Work Group chairperson, the Joint Task Force will discuss and resolve all relevant potential conflicts of interest associated with this selection. Finally, all members of parameter workgroups will be provided a written statement regarding the importance of ensuring that the parameter development process is free of commercial bias. Practice parameters are available online at www.jcaai.org and www.allergyparameters.org.

/pdf/the-diagnosis-and-management-of-acute-and-chronic-urticaria-46ajlm7qkp.pdf

The diagnosis and management of acute and chronic urticaria: 2014 update.

Urticaria and angioedema are common disorders affecting approximately 15-20% of the population at least once during their lifetime (Swinny, 1941; Sheldon et al., 1954; McKee, 1966). Urticarial lesions result from localized dilatation and transudation of fluid from small venules, and in their simplest form are thought to represent the same sort of wheal-and-flare reaction observed when histamine is injected into the skin. Clinically, one observes the presence of pruritic, erythematous cutaneous wheals that blanch with pressure, reflecting the underlying edema and dilated blood vessels. The histopathological features of urticaria are dilatation of cutaneous blood vessels and lymphatics in the superficial dermis, widening of dermal papillae, flattening of rete pegs, and swelling of collagen fibers.

http://www.fitzpatricksdermatology.com/references/Fitzpatricks_Derm8e_Ref_Ch038.pdf

Urticaria and Angioedema

Vitamin D and cancer.

Expression of 1,25-dihydroxyvitamin D3 receptors in normal and psoriatic skin.

Serological studies were performed in 3 patients with typical contact urticaria to latex surgical gloves. Specific IgE antibodies to natural latex as well as to vulcanized glove material have been detected by radioimmunoassay. Contact urticaria to latex is considered to be of the immunologic type.

Contact urticaria to rubber gloves is IgE-mediated.

6278 patients were patch tested with a sesquiterpene lactone mix (SL-mix) in 10 European clinics. 4011 patients were tested only with 0.1% SL-mix. 63 (approximately 1.5%) of whom were positive, with 26 (41%) of these cases being considered clinically relevant. There were no cases of active sensitization occurred though 5 eases of irritation were reported. 22 irritant reactions and 22 cases of active sensitization occurred when testing also with 1% and 0.33% concentrations of SL-mix. SL-mix 0.1% pet is shown to be an important patch test and many relevant sensitizations will be missed without routine screening with such a mix. Most patients with SL-mix sensitivity presented with hand and/or face dermatitis, apparent photodermatitis or more generalised eczema.

Patch testing with the "sesquiterpene lactone mix": a marker for contact allergy to Compositae and other sesquiterpene-lactone-containing plants. A multicentre study of the EECDRG.

Two patients, a father and a daughter, with atrophoderma vermiculatum are presented. The chief characteristics of this rare, benign condition that usually begins in childhood are a symmetric worm-eaten or reticular atrophy of the cheeks that may extend to the ears or forehead. An autosomal dominant mode of inheritance is present in this family. The prominent characteristics, cause, histologic findings, and rare associated medical conditions are reviewed. The prognosis is good, with many instances of spontaneous regression. Primarily a cosmetic problem, therapy for this condition is aimed at reassurance, genetic counseling, and dermabrasion where appropriate.

Atrophoderma Vermiculatum. Case Reports and Review

A total of 8149 patients were patch tested with the preservative Bronopol in 7 European contact clinics. The Majority of patients (6507) were investigated in London. Reactivity was low, with a total of 10 irritant (0.12%) and 38 allergic reactions (0.47%). In only 17 cases (0.21%) was the patch test reaction to Bronopol considered to be of current or past clinical relevance. Concomitant sensitization to formaldehyde was present in about 1/3 of patients. Based on these figures, the present sensitization rate to Bronopol in Europe seems to be quite low, which may be related to its less frequent use as a preservative in cosmetics and medicaments in comparison to parabens or isothiazolinones.

Frosch Pj

Papers

Expression of 1,25-dihydroxyvitamin D3 receptors in normal and psoriatic skin.

Contact urticaria to rubber gloves is IgE-mediated.

Patch testing with the "sesquiterpene lactone mix": a marker for contact allergy to Compositae and other sesquiterpene-lactone-containing plants. A multicentre study of the EECDRG.

Atrophoderma Vermiculatum. Case Reports and Review

Contact allergy to Bronopol.