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Monographs of fragrance chemicals and extracts that have caused contact allergy / allergic contact dermatitis
Published in Anton C. de Groot, Monographs in Contact Allergy, 2021
The hypothesis that patients sensitized to p-phenylenediamine are at increased risk of concomitant reactivity to limonene hydroperoxides, owing to a ‘common pathway’ of skin protein oxidation, has been rejected (65).
3-(Aminomethyl)Pyridyl Salicylate
Published in Anton C. de Groot, Monographs in Contact Allergy, 2021
A cross-reaction has been suggested with p-phenylenediamine (PPD) and other para-compounds (2, 4). Two of two patients (2), one of one (1) and 9 of 11 (4) were allergic to both 3-(aminomethyl)pyridyl salicylate and PPD, some of who also to other para-substances such as benzocaine and aniline (2, 4). No cross-reaction to ethyl salicylate or methyl salicylate (4).
Common Office Tests and Procedures for the Allergist
Published in Pudupakkam K Vedanthan, Harold S Nelson, Shripad N Agashe, PA Mahesh, Rohit Katial, Textbook of Allergy for the Clinician, 2021
Patch tests should be kept in place for 48 hours, then removed for interpretation. After the first reading (at 48 hours), an additional reading at 72–96 hours is recommended to reduce false-positives (i.e., positive at first reading but negative at second reading) and false negatives (i.e., negative at first reading but positive at second reading). Approximately 30% of relevant allergens that are negative at the 48 hour reading become positive at 72–96 hours. Conversely, irritant reactions at 48 hours tend to disappear by 72–96 hours. For weak sensitizers such as neomycin or p-phenylenediamine, additional readings at 5–7 days may be necessary.
Comparison between patch test results of natural dyes and standard allergens in batik workers with occupational contact dermatitis
Published in Cutaneous and Ocular Toxicology, 2022
Eka Devinta Novi Diana, Suci Widhiati, Moerbono Mochtar, Muhammad Eko Irawanto
Some standard allergen properties are thought to cause ACD, including having a small molecular weight (less than 500 Da), being electrophilic, and being a strong sensitiser. The study of Handa et al. in India reported that a positive patch test for PPD of 0.1% was found in 13% of cases18. In this study, out of 5 subjects with ACD due to exposure to standard allergens, a positive patch test for 0.1% PPD was found in 1 subject (20%). P-phenylenediamine is a hapten with a small molecular weight of 108.1 Da. The low molecular weight of PPD facilitates the penetration of allergens into the stratum corneum, which in turn causes sensitisation. P-phenylenediamine easily binds to proteins to form a complete antigen and is electrophilic. P-phenylenediamine sensitisation of the skin is thought to be due to the formation of benzoquinone. P-phenylenediamine, which is exposed to oxygen (O2) in the air for a long time, will be oxidised to reactive benzoquinone diimine, a necessary substance to react with proteins19.
The effects of para-phenylenediamine (PPD) on the skin fibroblast cells
Published in Xenobiotica, 2019
Enayatollah Seydi, Mohsen Fatahi, Parvaneh Naserzadeh, Jalal Pourahmad
The use of hair dye has roots in the past times and in Egypt. Furthermore, the hair dye has been used to enhance the attractiveness, health, femininity and beauty (Al-Shaikh et al., 2018). One of the most important components of the hair dye is para-phenylenediamine (PPD), which is a derivative of para-nitroaniline (Abd-ElZaher et al., 2012; Al-Shaikh et al., 2018; Blömeke et al., 2009; Chye et al., 2014; Hooff et al., 2011; Singla et al., 2005). Research has shown that about 30% of American women use PPD containing hair dyes (Abd-ElZaher et al., 2012). Documents show that the toxicological properties of aromatic amines such as PPD are very widespread. One of these important properties is the induction of apoptosis through increased reactive oxygen species (ROS) (Chye et al., 2014; Nohynek et al., 2015). The most important route of exposing humans to PPD is through the skin and inhalation during the dyeing process (Abd-ElZaher et al., 2012). PPD can cause skin irritation, contact dermatitis, rhabdomyolysis, renal impairment and severe edema. These complications indicate that this compound is very toxic (Al-Shaikh et al., 2018; Singla et al., 2005).
Assessment of pre and post-thymectomy myasthenia gravis
Published in Neurological Research, 2019
Suresh C. Bokoliya, Shripad A. Patil
AChR ELISA (Imgenex, USA) was used to detect anti- AChR antibodies. Assay performed according to the manufacturer’s protocol. The test validated and it is in routine clinical use at the Department of Neuromicrobiology, NIMHANS. Briefly, AChR precoated ELISA plates were used to detect anti-AChR antibodies. Test sera added (50 μl/well) in duplicates with controls. ELISA plates were incubated for 90 minutes at 37°C and following incubation plates were washed five times with wash buffer. Horse radish peroxidase conjugated rabbit anti-human polyclonal IgG added (50 μl/well) as secondary antibody and plates were incubated for 60 minutes at 37°C. After incubation, plates were washed five times with wash buffer. Ortho-phenylenediamine added (50 μl/well) as substrate and plates were incubated for 5–10 minutes in dark chamber for colour development. ELISA plate reader (Magllen,Tecan AG., Austria Gmbh) was used to measure reaction absorbance at 490 nm. The positive cut-off (0.300 OD) calculated on the basis of the mean + 3 standard deviation (SD) of the values of control sera. Below this cut-off, serum sample denoted as negative for anti-AChR antibodies.