China 
Africa 
Explore chapters and articles related to this topic
Allergic Responses to Powdered Natural Rubber Latex Gloves in Healthcare Workers
Published in Robert N. Phalen, Howard I. Maibach, Protective Gloves for Occupational Use, 2023
Delayed-type hypersensitivity to NRL gloves may also occur. The gold standard in the diagnosis of type IV hypersensitivity is patch testing. In addition to standard series (i.e. European Baseline Series, North American Baseline Series) and rubber additive series, patch testing with patients' own glove materials is highly recommended in patients with glove-related symptoms.28 The glove can be cut off into 2 × 2 cm pieces, and both the internal and external surfaces of the gloves should be tested as the allergens on these surfaces may differ. The glove pieces can be applied to the upper back using adhesive tapes, and the first reading is done at 48 hours. The rubber compounds in the European Baseline Series are detailed in Table 17.4. In a study of 148 patients with suspected rubber-related ACD, 2% had a positive patch test reaction to NRL. An important point in patch testing with NRL is that an early reading at 20–30 minutes is essential to detect patients with immediate hypersensitivity.29
Consumer Safety Considerations of Cosmetic Preservation*
Published in Philip A. Geis, Cosmetic Microbiology, 2020
Corie A. Ellison, Alhaji U. N’jai, Donald L. Bjerke
Skin sensitization, also known as delayed contact hypersensitivity, is an immunologically mediated allergic response and is classified as a type IV response according to the scheme of Combs and Gell (28). The key factors characterizing type IV reactions are typically delayed onset of symptoms that get worse over a 24–72-hour timeframe. The symptoms typically involve pruritis, erythema, and edema and can progress to vesicle formation. These symptoms can also spread beyond the site of application of the product. Type IV reactions are associated with IgG antibodies. Poison ivy allergic contact dermatitis is a classic example of delayed type IV hypersensitivity. One way type IV sensitization can be distinguished from the irritation responses discussed is that the poison ivy rash-like sensitization, intense itching, and vesiculation response will likely spread beyond the site of exposure of the chemical insult, while the irritation response (typically with less edema than sensitization) tends to be localized to the initial area of the insult, and the skin response will typically persist for a longer period. In addition, induction of skin sensitization is a permanent change because memory cells within the immune system will remember the original exposure and the individual may react to any future exposures to the allergen that are above the threshold for elicitation of allergic contact dermatitis.
Inflammation and the Immune System
Published in Jeremy R. Jass, Understanding Pathology, 2020
An excessive response by the immune system to an antigenic stimulus that is damaging to the host is described as hypersensitivity. The antigen may be exogenous or derived from within the organism itself. The latter is described as autoimmunity and is discussed in Chapter 30. The Gell and Coombs classification of hypersensitivity reactions (Table 3) stems from the days of old immunology. Types I, III and IV hypersensitivity were described initially in 1902, 1905 and 1891 respectively (Bordley & Harvey, 1976). Only type IV hypersensitivity recognises the participation of the T lymphocyte. A single disease process may implicate two or more types of hypersensitivity. For example, types I, III and IV hypersensitivity are implicated in pulmonary aspergillosis (fungal infection) and types II and IV participate in antibody-dependent cellular cytotoxicity (ADCC). Type III hypersensitivity is responsible for most types of glomerulonephritis, yet this group of kidney disorders shows considerable variability in terms of morphology, natural history and prognosis. This is explained at least in part by the size and number of immune complexes bombarding the glomerulus. The classification of hypersensitivity given in Table 3 is therefore an oversimplification but still retains its popularity.
Computed tomography in hypersensitivity pneumonitis: main findings, differential diagnosis and pitfalls
Published in Expert Review of Respiratory Medicine, 2018
Olívia Meira Dias, Bruno Guedes Baldi, Francesca Pennati, Andrea Aliverti, Rodrigo Caruso Chate, Márcio Valente Yamada Sawamura, Carlos Roberto Ribeiro de Carvalho, André Luis Pereira de Albuquerque
The inhaled particle must have an aerodynamic diameter between 1 and 3 μm to reach the pulmonary acini, depositing in the terminal airways and alveoli. With continuous exposure, a type IV hypersensitivity response occurs. There is persistent and unrepaired epithelial cell damage with stimulation of interleukin (IL)-12 secretion by macrophages, thus promoting the differentiation of lymphocytes into a T-helper cell 1 (Th1)-like response. Immunocomplexes bind to Fc receptors on the surface of lymphocytes, stimulating the production of ILs, mainly tumor necrosis factor (TNF)-α and IL-1. These stimulate Th1 lymphocytes to produce interferon-γ. The latter further stimulates the production of TNF-α, transforming growth factor-β, and IL-1, generating a positive feedback mechanism that culminates in the chemoattraction of fibroblasts, increased local production of collagen, interstitial remodeling, and, finally, fibrosis. Some authors also postulated that the inability of the lymphocyte to eliminate a given antigen would polarize the immune response to Th2, resulting in a greater chance of disease progression to chronic HP with fibrosis [13,14].
Understanding Retinal Vasculitis Associated with Brolucizumab: Complex Pathophysiology or Occam’s Razor?
Published in Ocular Immunology and Inflammation, 2022
Ashish Sharma, Nilesh Kumar, Nikulaa Parachuri, Sonali Singh, Francesco Bandello, Carl D. Regillo, David Boyer, Quan Dong Nguyen
Extensive uveitis work-up was negative in the cases published. An expert panel disproved the need for a systemic workup to find a probable source of an embolic occlusion.13 Furthermore, the involvement of only the injected eye (no bilateral event) and mean age-group makes it less likely to be due to immunogenicity secondary to systemic autoimmune mechanism. Interestingly, all 15 published cases were females. The ASRS communication revealed that 88% of the cases reported to the ReST committee were females. We agree that female preponderance is seen in cases of systemic autoimmune diseases although this limited data set cannot conclusively implicate any causative association. In the brolucizumab data, 8 out of the 15 case reports revealed an underlying presence of DM, arthritis or multiple sclerosis, all of which have some auto-immune pathophysiology. Three cases were reported in the patients having breast cancer. Rosenbaum et al., have shown that patients with retinal vasculitis rarely suffer from systemic vasculitis and it is more commonly associated with local uveitis.14 The systemic immune reaction may thus not be a causative factor but can be a predisposing factor in the reactions related to vasculitis post-brolucizumab. The recently published report from Iyer et al gives us the first histopathological evidence about the nature of inflammation in the vitreous of one such case.8 It concludes the presence of inflammatory cells to be in favor of a type IV hypersensitivity reaction. The report though didn’t analyze the histopathological sample from the vessels involved to provide conclusive evidence.
Rhodotorula minuta as a hypersensitivity pneumonitis causative agent in contaminated continuous positive airway pressure device: A case report
Published in Canadian Journal of Respiratory, Critical Care, and Sleep Medicine, 2022
Florence Côté, Marie-Eve Bédard
Hypersensitivity pneumonitis (HP), also known as extrinsic allergic alveolitis, is an inflammatory response to an inhaled antigen in a previously sensitized individual. It has been classified as a type IV hypersensitivity reaction.1 It can present in a variety of signs and symptoms, often mimicking infections or other respiratory conditions. The pathologic and radiologic imaging findings normally point to the spectrum of interstitial lung diseases (ILD).2