Common Irritants Research Articles

Perceptions of skincare ingredients and product labels in pediatric eczema care.

Educating pediatric eczema patients and caregivers on appropriate product selection and avoidance of common irritants or allergens is a crucial aspect of eczema management. This study surveyed 80 pediatric caregivers in an academic pediatric dermatology clinic to assess influential factors in caregivers' selection of pediatric eczema-care products and identify ways to improve patient counseling on appropriate product selection and avoidance of common irritants or allergens. Caregivers frequently reported positive perceptions of commonly recommended ingredients for eczema but had inconsistent perceptions of fragrant plant oils and extracts, regardless of previous counseling on fragrance avoidance. These findings demonstrate uncertainty and misperceptions perpetuated by product labeling and a need for improved counseling strategies for avoiding fragrance and excessive product costs.

Identifying Fraud Detection Techniques Using Text Analytics Processing

To determine the fraud detection model, to illustrate how the fraud detection model is created, and to start the data model with any classifier, data mining technology is used in the fraud detection process. As e-commerce continues to grow, the associated internet hoax is still a very appealing source of cash for scammers. Because of the severe financial damage that this counterfeit activity does to retailers, online fraud detection is essential. Concerned with scam detection is the need to quickly seize fraudulent actions in addition to containing them. This significance is essential to reducing financial losses. Cybercrimes are a widespread annoyance and have a negative impact on our society in many ways. In every nation, the police enforcement system heavily relies on the results of cybercrime investigations. The connected online hoax is still a highly alluring way for con artists to get money as e-commerce expands. Online fraud detection is crucial due to this counterfeit activity's significant financial harm to merchants. In addition to curbing fraudulent acts, scam identification raises the urgent need to seize them. To minimize financial losses, its relevance is crucial. Cybercrimes are a common irritant that harms our society in a variety of ways. The outcomes of cybercrime investigations substantially influence the police enforcement systems in every country. These methods are essentially utilized for fraud detection in a variety of industries, including health, insurance, online shopping, and more.

Identifying the vagal bronchopulmonary afferents responsible for eliciting the cough response to inhaled sulfur dioxide in mice

Among the three major types of vagal sensory nerves innervating the lung and airways, C‐fibers and rapidly adapting receptors (RARs or irritant receptors) are known to possess the properties and functions of “cough receptors”, but their relative roles in regulating cough reflex responses to inhaled irritants are not yet clearly defined. To address this question, we have recently carried out a series of studies in a mouse cough model, in which the intra‐pleural pressure was continuously recorded by a surgically implanted telemetry sensor. Sulfur dioxide (SO2), a common irritant gas, was chosen for the study because its widespread use as a chemical agent in various industrial operations has led to severe lung injuries in workers in numerous incidences resulting from accidental release of high concentrations of SO2 in industrial facilities. Inhalation of SO2 (300 and 600 ppm) consistently and reproducibly elicited coughs in a concentration‐dependent manner in awake mice moving freely in a recording chamber. The cough frequency increased rapidly after the onset of the SO2 inhalation challenge, which continued for the remaining duration of 8‐min exposure. In the current study, single‐fiber electrophysiological recording of vagal afferent activity in anesthetized mice showed that the high concentration of SO2 (600 ppm) evoked a sustained stimulatory effect on C‐fibers for the entire duration (8 min) of the inhalation challenge. However, in sharp contrast, inhalation of SO2 at the same concentration and duration generated a distinct and consistent inhibitory effect on both phasic RARs and slowly adapting receptors. Their respiratory cycle‐related phasic discharge declined progressively and/or ceased completely within 1‐3 min after the onset of the SO2 inhalation challenge, which gradually recovered after >15 min following the termination of the SO2 inhalation. In a small percentage of RARs that displayed no phasic activity during eupneic breathing and often exhibited sensitivity to certain inhaled irritants, the same SO2 inhalation challenge did not evoke any significant stimulatory effect. Taken together, these observations suggest that stimulation of bronchopulmonary C‐fibers is primarily responsible for triggering airway irritation and coughing in response to the SO2 inhalation challenge.

Otological Manifestations in Oral Submucous Fibrosis

Oral submucous fibrosis (OSMF) is a chronic and progressive disease where fibrous bands formed in the oral mucosa, resulting in severe restriction of movements of the jaw and also tongue. OSMF is one of the commonly seen potentially malignant disorders which can cause severe morbidity. It is prevalent in the Indian subcontinent. The exact etiology of OSMF is not known. Chronic irritation of the oral mucosa is thought to be the underlying etiology for OSMF. The common irritants are betel nut, tobacco, and chilies. The pathological changes not only affect mucosa and submucosa of the oral cavity and pharynx but also affect deeper parts with the involvement of underlying muscles. Atrophic and degenerative changes in the tubal and paratubal muscles of the eustachian tube, leading to eustachian tube dysfunctions. The eustachian tube dysfunction in OSMF results in different otological symptoms such as hearing impairment, otalgia, and fullness in the ear. Dysfunction of the eustachian tube in OSMF may be due to fibrosis in the palatal muscles, resulting in a conductive type of hearing loss. While treating OSMF, otological manifestations such as eustachian tube dysfunctions and hearing impairment have to be kept in mind and vice versa because managing hearing disability without taking care of OSMF will not be successful. All literature related to otological manifestations in OSMF were identified through Scopus, Google Scholar, Medline, and Pub Med and analyzed individually. This review article discusses the etiopathology, epidemiology, clinical manifestations, and management of the OSMF with otological manifestations.

Botanical Briefs: Phytophotodermatitis Is an Occupational and Recreational Dermatosis in the Limelight.

Phytophotodermatitis (PPD) is a toxic reaction resulting from contact with a photosensitizing botanical chemical followed by exposure to solar or artificial UV light. It may present with bizarre patterns and linear streaks due to a phototoxic agent splashing onto various cutaneous sites; thus, it affects the skin at points of contact and exposure to UV light. Individuals typically experience symptoms within 24 hours of exposure. Children and adolescents seem particularly prone to developing PPD, as they tend to spend time in the sun and also may come into contact with common irritants such as wild parsley in lawn grass or beverages flavored with lime. However, PPD may be more than a recreational dermatitis; it also may represent a serious occupational dermatosis. In any case, the resultant acute dermatitis may be mild or severe with painful bullae and occasionally is more prominently evident as postinflammatory hyperpigmentation.

Persistent Diaper Rash in a 5-month-old Girl

1. Joana Matos, MD* 2. Joao Tavares, MD† 3. Susana Machado, MD‡ 4. Manuela Selores, MD‡ 1. *Servico de Pediatria do Centro Hospitalar do Tâmega e Sousa, Penafiel, Portugal 2. †Hospital Pediatrico, Centro Hospitalar da Universidade de Coimbra, Coimbra, Portugal 3. ‡Servico de Dermatologia do Centro Hospitalar do Porto, Porto, Portugal A previously healthy 5-month-old girl is referred to pediatric dermatology for a diaper rash persisting for more than 2 months despite antifungal treatment and several barrier creams. She is otherwise asymptomatic and has no relevant medical history. The family history is significant for her father with episodic erythematous lesions over the forearms and legs. Physical examination reveals a well-defined, bright, erythematous plaque affecting the perineal area, including the groins and upper thigh, with minimal peripheral scaling (Fig 1). She also has 2 smaller satellite lesions in the left thigh. There are no other abnormal findings on physical examination. The clinical features and family history suggest the diagnosis. Figure 1. Erythematous plaque in the diaper area at presentation. Many dermatoses affect the diaper region, including the most common irritant, contact dermatitis. More diffuse skin diseases and systemic disorders that can manifest with specific diaper region symptoms may include inflammatory dermatoses such as seborrheic dermatitis or psoriasis, infections (eg, Candida albicans infection, perianal streptococcal and staphylococcal dermatitis), and metabolic disorders such as acrodermatitis enteropathica or neoplasia (eg, Langerhans cell histiocytosis). Immersion burns resulting from either inadvertent or intentional immersion in hot water or other liquid may also appear with a well-delimited erythematous diaper area rash. Based on the clinical features and suggestive family history, the patient was diagnosed as having psoriasis and was prescribed an antifungal and corticosteroid combination cream plus a zinc oxide–based repair ointment. Psoriasis is …

Cough response to sulfur dioxide inhalation challenge is enhanced by tumor necrosis factor alpha: a primary role of vagal bronchopulmonary C‐fibers

Tumor necrosis factor alpha (TNFα), a pro‐inflammatory cytokine, plays a significant role in the pathogenesis of asthma. We recently reported that TNFα pretreatment elevated the sensitivities of vagal bronchopulmonary C‐fibers and silent rapidly adapting rectors (RARs) to capsaicin (Front. Physiol. 2017). In this study, we investigated the effect of TNFα on cough response to sulfur dioxide (SO2), a common irritant gas, and the relative contributions of these vagal afferents. Our results showed: 1) Inhalation of SO2 (300 and 600 ppm; 8 min each) consistently elicited coughs in a concentration‐dependent manner in awake mice moving freely in a recording chamber; coughs were recorded via telemetry sensors implanted in the intrapleural space. The cough frequencies during and immediately after the SO2 inhalation challenges increased markedly in the same animals after TNFα (10 μg/ml; 0.03 ml) was administered into the lung by intratracheal instillation, and this increase in cough sensitivity sustained for >7 days after the TNFα pretreatment. In contrast, the cough response to SO2 inhalation challenges did not change after pretreatment with vehicle (0.03 ml of PBS) in a matching group of control mice. 2) In single‐fiber recording experiments in anesthetized mice, the same SO2 inhalation challenges (for 8 min) evoked a pronounced stimulatory effect on C‐fiber afferents, reaching a peak in 1–4 min. The increased fiber activity was concentration dependent and lingered for several more minutes after the termination of SO2 challenge. This stimulatory effect of SO2 was significantly elevated in the TNFα‐treated mice. 3) The same SO2 inhalation challenges, either 300 or 600 ppm, did not activate any of the silent RARs in vehicle‐treated mice, and only 600 ppm SO2 caused a very weak stimulation in 2 out of 7 of these silent RARs in TNFα‐treated mice. 4) Inhalation of SO2 (300 or 600 ppm) consistently induced an inhibitory effect on both slowly adapting receptors and phasic RARs; these afferents ceased to discharge completely in 1–5 min after the onset of SO2 (600 ppm) inhalation challenge, and a majority of them slowly returned to controls after resuming air breathing for >1 hr. No detectable difference in this inhibitory effect was found between TNFα‐ and vehicle‐treated mice. In conclusion, the cough response to SO2 inhalation challenge is enhanced by the TNFα pretreatment in wake mice, and an increase in the bronchopulmonary C‐fiber sensitivity to SO2 is primarily responsible.Support or Funding InformationNIH grant AI123832This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Maternal Competition in Women

We examined maternal competition, an unexplored form of competition between women. Given women's high investment in offspring and mothers' key role in shaping their reproductive, social, and cultural success as adults, we might expect to see maternal competition between women as well as mate competition. Predictions about the effect of maternal characteristics (age, relationship status, educational background, number of children, investment in the mothering role) and child variables (age, sex) were drawn from evolutionary theory and sociological research. Mothers of primary school children (in two samples: N=210 and 169) completed a series of questionnaires. A novel nine-item measure of maternal competitive behavior (MCQ) and two subscales assessing Covert (MCQ-C) and Face-to-Face (MCQ-FF) forms of competition were developed using confirmatory factor analysis. Competitiveness (MCQ score) was predicted by maternal investment, single motherhood, fewer children, and (marginally) child's older age. The effect of single motherhood (but not other predictors) was partially mediated by greater maternal investment. In response to a scenario of their child underperforming relative to their peers, a mother's competitive distress was a positive function of the importance she ascribed to their success and her estimation of her child's ability. Her competitive distress was highly correlated with the distress she attributed to a female friend, hinting at bidirectional dyadic effects. Qualitative responses indicated that nonspecific bragging and boasting about academic achievements were the most common irritants. Although 40% of women were angered or annoyed by such comments, less than 5% endorsed a direct hostile response. Instead, competitive mothers were conversationally shunned and rejected as friends. We suggest that the interdependence of mothers based on reciprocal childcare has supported a culture of egalitarianism that is violated by explicit competitiveness.

Avocational Contact Dermatitis—Pearls for Recognition and Management

Avoidance is the principle treatment for all types of contact dermatitis. The myriad of potential hobbies and recreational activities can make recognizing and managing avocational contact dermatitis challenging. For this reason, it is important to become familiar with some of the more common irritants and allergens encountered. Key Points 1. An avocation is a recreational activity or hobby which may lead to exposure of potential cutaneous irritants and allergens. 2. Many cases of avocational contact dermatitis present as hand dermatitis. 3. Prevention is the best strategy for avocational contact dermatitis.

Relationship between the response to allergen, histamine and hypertonic saline nasal challenge and subjective reactivity to irritants in subjects with seasonal allergic rhinitis

Background Patients with seasonal allergic rhinitis (SAR) may have symptoms triggered by environmental changes and irritants exposure in the absence of allergen. It is hypothesized that level of hyperreactivity in mixed rhinitis is related the inflammation in the late phase response, stimulation of sensory nerves and transient receptor potential (TRP) channels. The study was done to compare subjective and objective response to the low-dose allergen, histamine and hypertonic saline challenge, with subjective responsiveness to common irritants.

Gold contact allergy: clues and controversies.

In 2001, gold was named Contact Allergen of the Year. More than a decade later, we continue to face several challenges in defining the role of gold in contact allergy. First, interpretation of gold reactions in the setting of epicutaneous patch testing may be difficult; in addition to being a common irritant, gold may be associated with significantly delayed and persistent reactions. Second, although gold compounds are commonly positive on patch testing, clinical relevance is relatively low and may be challenging to determine. Third, the complex interplay between gold and the human body is still poorly understood. In this review, we provide an overview of the literature concerning gold patch test positivity and present recommendations for epicutaneous patch testing with gold.

Correlative ultrastructural investigations of airway epithelium following experimental exposure to defined air pollutants and lifestyle exposure to tobacco smoke

Context: Investigations of cell/molecular level effects of in vivo exposure of airway mucosa of experimental animals to common irritant gases have demonstrated structural and physiological changes reflective of breaches in epithelial barrier function, presence of inflammatory cell infiltrate and compromised ciliary function. These experimental animal studies provided useful perspectives of plausible, but more subtle pathologic outcomes having relevance to lifestyle exposure to gaseous environmental irritants including tobacco smoke.Methods: Freeze-fracture technology was applied to ultrastructural examination of large airway epithelium, with appropriate controls, from guinea pigs exposed to ozone and of nasal mucosa of human subjects exposed to ozone or sulfur dioxide, and nasal mucosa of active smokers.Results: We documented substantive membrane structural changes to tight junctional complexes and cilia as well as an infiltrate of neutrophils into the surface mucosal layer in exposed animals. These patterns also were evident but not as pervasive among human subjects acutely exposed experimentally to irritant gases and those chronically exposed by their lifestyle to tobacco smoke.Discussion: Our intent was to characterize respiratory tract mucosal membrane disorganization associated with high level acute irritant exposures in an experimental animal model and to evaluate evidence of similar but perhaps more subtle pathologic change associated with lower level experimental or lifestyle exposures. Our studies demonstrate continuity, albeit subtle, of pathologic change from high dosage experimental animal exposure to low dosage human exposures.Conclusions: This study represents the first report of ultrastructural airway epithelial membrane anomalies associated with lifestyle exposure to tobacco smoke irritants.

Acute bacterial meningitis in childhood: analysis of 20 cases

We aimed to retrospectively evaluate our cases with the diagnosis of bacterial meningitis in view of their clinical and laboratory findings. Demographic features of the patients, physical examination and laboratory findings were achieved by screening the files. The diagnosis of meningitis made in the light of clinical and laboratory findings. Average age of 20 patients in the study was 4.74±4.55 years (2 months-14 years). Eleven patients (55%) were vaccinated completely. Nine patients (45%) started to oral antibiotics treatment before their application. The most common application complaints of patients were high fever and vomiting. In the physical examination the most common fever and meninx irritation in the 50% of the cases were present. In the culture of 4 of five (25%) patients, reproduction of Streptococcus Pneumoniae and reproduction of Neisseria Meningitidis in 1 patient were seen. Complication was developed in 55% of the patients (11 patients). 5 convulsions, 4 papilledema, and 2 seventh nerve palsy were detected in these cases. Sixth nerve palsy was present in 3 of 4 papilledema cases. Among the findings with convulsion, subdural effusion was detected in 1 and cerebral abscess was detected in the others. All of the patients were treated medically. The case with cerebral abscess was treated surgically. Sequel was not developed in none of the cases. Acute bacterial meningitis is still a serious health problem in our country. Vaccination, early diagnosis, and effective antibiotic usage decrease meningitis based mortality and morbidity ratios.

Environmental pollutants and allergic rhinitis

To review the current knowledge of the pathophysiology, epidemiology, and management of environmental pollutants and allergic rhinitis. Both active cigarette smoking and passive exposure to cigarette smoke are associated with chronic rhinitis and sinusitis. Matrix metalloproteinase 9, which is thought to contribute to the pathophysiology of allergy, is elevated in children with passive cigarette smoke exposure compared with controls. Ground-level ozone and particulate matter exposure is associated with an allergic-type response and may increase sensitization to other allergens. Certain occupational exposures can cause nasal irritation and local cytotoxic effects. Evidence suggests that rhinitis symptomatology may often precede the development of occupational asthma. Environmental factors have been noted to induce sinonasal mucosal irritation and often contribute to the multifactorial cause of chronic rhinitis and allergic rhinitis. Cigarette smoke is a common irritant that impacts the innate immune function of the sinonasal epithelial cells, and creates local irritation and cytotoxic effects. Both active smoking and exposure to second-hand smoke increase the risk of chronic rhinitis. Many other environmental pollutants are associated with chronic rhinitis, including ozone, particulate matter, and occupational irritants. The management of chronic rhinitis associated with environmental exposures is similar to the management of other types of chronic rhinitis. Although often not feasible, avoidance is probably the most effective course.

OA01.12. A clinical study of efficacy of Vyoshadi gutika and Pippalayadi churna avapida nasya in the management of Pratishyaya

Purpose: Pratishyay basically is a Vat-kaphaj disorder arising from accumulation of vitiated Vat along with kaph-pitta-rakta in uttamang (shirh pradesh) and comparable to Rhinitis which describes a group of symptoms including runny nose, stuffiness, sneezing usually due to common cold, environmental irritants and immunodeficiency. This study aim to do 1.Evaluation of effectiveness of Vyoshadi gutika (samshaman therapy) and Pippalayadi churna Avapida nasya (samshodhan therapy) in the management of pratishyay, 2.Statistical assessment of data post treatment. Method: 60 patients of Pratishyay aged between 16-60 years of age of both sexes complaining of Rhinorrhoea/ nasal block, sneezing, heaviness of head, anosmia were selected randomly and assigned for clinical study were divided into 2 groups. Group A consisting of 30 patients had internal administration of Vyoshadi gutika in a dose of 2 tablets QID (each tab. 375 mg) with lukewarm water for 30 days. Group B- 30 patients took Vyoshadi gutika along with Pippalayadi churna Avapida nasya (6 drops in each nostril early morning) for duration of 21 days. All patients were advised to attend 15 days Intercal regularly for 3 months for assessment of disease through subjective and objective parameters. Result: 60% patients (18 no.) of Group B while 47% patients (14 no.) Group A responded satisfactorily with maximum improvement (more than 76% symptomatic improvement). Similarly, Moderate improvement (between 51-75%) was seen in 47 patients of Group A and 37% of Group B while mild improvement in 10% and 3% patients of Group A and B respectively. No untoward adverse effects were seen in any patients. Conclusion: It can be concluded that on the basis of Practical, Therapeutic and Statistical analysis, patients of both groups got satisfactory improvement. Besides, patients treated with both Samshodhan Nasya therapy and Samshaman Vyoshadi Gutika therapy comparatively got better results.

中国北部ゴビ砂漠周辺におけるＣＯＰＤ患者の肺機能と黄砂発生との関係―黄砂多発地域における受診記録の分析より―

Chronic obstructive pulmonary disease (COPD) is a progressive and chronic lung disease with obstructed lung airflow mainly caused by an inflammatory response. The most common irritant that causes COPD is smoking because of its ability to infringe the whole lung. Breathing the chemical fumes or dusts from the environment also can cause COPD.Dust and sandstorm (DSS) is a serious environmental phenomenon in Northeast Asia. Recently, alkaline DSS adsorb the acid chemicals discharged from the industrial areas of People’s Republic of China (PRC), and the sorbents are considered as a risk factor of the lung disease. In the large city, number of patients visited the respiratory division have increased during the DSS occurrence days.Thus, this study examined the clinical records of the COPD patients admitted to the hospital near the Gobi-Desert in PRC to assess the relationship between the DSS outbreak and the impairment of the lung function.Significantly lowered lung functions and the increased allergic reactions were observed in the people who stayed in the air polluted area and exposed to DSS for a long time.These results suggest that restriction of not only smoking but also DSS inhalation, might be important for the COPD treatment, and the anti-allergic treatment seemed to be effective to suppress the inflammation, especially for the elderly patients.

Can the reporting of adverse skin reactions to cosmetics be improved? A prospective clinical study using a structured protocol

The use of cosmetics is rising, and adverse reactions to these products are increasing. In Sweden, the Medical Products Agency (MPA) keeps a voluntary reporting system for such adverse reactions. However, the reporting is sparse, consisting almost only of cases with test-proven allergic contact dermatitis, thus under-reporting the more common irritant reactions. The aim of the study was to try to improve the reporting system. Dermatologists at 3 dermatology departments used a structured protocol during the clinical investigation of 151 consecutive patients reporting skin reactions to cosmetics. The protocol included symptoms, signs, affected body site, suspected products, and final diagnosis after patch testing. Based on clinical data and patch test results, a causality assessment for each product was made according to a protocol used at the MPA. Allergic contact dermatitis was found in 28% of the patients, and irritant reactions were equally common at 27%. Using this structured protocol, the cases of irritant dermatitis were also reported, and it is recommended that such a protocol is used as a standard to improve the reporting of adverse reactions to skin care products.

Patterns of Global Tobacco Use in Young People and Implications for Future Chronic Disease Burden in Adults

Warren CW, Jones NR, Eriksen MP, Asma S; Global Tobacco Surveillance System (GTSS) Collaborative Group. Lancet. 2006;367:749–753 PURPOSE OF THE STUDY. The Global Youth Tobacco Survey assessed current tobacco use and exposure among young teenagers and evaluated susceptibility to starting smoking among nonsmokers. STUDY POPULATION. Students aged 13 to 15 years (N = 747 603) at 395 sites in 131 countries and the Gaza Strip and West Bank. METHODS. Students completed questionnaires to assess current tobacco use, cigarette smoking, susceptibility to smoking among nonsmokers, and exposure to secondhand smoke in homes and public places. Susceptibility to smoking was defined as an answer other than “definitely not” when asked if they would smoke a cigarette offered by a best friend or if they thought they would smoke at any time in the next 12 months. RESULTS. Among all students, 17.3% currently used tobacco products and 8.9% currently smoked cigarettes. Current tobacco-product use was highest in the region of the Americas (22.2%), and current cigarette smoking was highest in the European region (17.9%) and region of the Americas (17.5%). Among students who had never smoked cigarettes, 18.3% reported susceptibility to smoking during the coming year. Susceptibility was highest in the European region (30.5%) and the region of the Americas (24.8%). Measures of use, susceptibility, and exposure were similar for boys and girls. Worldwide, never-smokers were less likely than current smokers to report exposure to secondhand smoke at home (prevalence: 39.1% [95% confidence interval (CI): 36.6–41.6] vs 72.8% [95% CI: 64.0–81.6]) and in public places (prevalence: 49.5% [95% CI: 46.7–52.3] vs 81.2% [95% CI: 74.2–88.2]). CONCLUSIONS. Although tobacco exposure and susceptibility remain high among young teenagers, this study demonstrated a significant association between lower secondhand cigarette-smoke exposure and never smoking. REVIEWER COMMENTS. Cigarette smoke is a common respiratory irritant that contributes to exacerbations of childhood asthma and rhinitis. This study provided evidence supporting the association between lower secondhand cigarette-smoke exposure and never smoking among young teenagers, which suggests an additional reason to counsel patients and their families regarding the immediate and long-term risks of exposure to secondhand cigarette smoke and cigarette smoking.

Three Distinct Categories of Time Course of Pain Produced by Oral Capsaicin

Humans vary in oral pain tolerance. Our earlier studies noted that the responses of subjects show 1 of 3 qualitative response patterns to a single oral capsaicin concentration, which we termed a tonic pattern (level detection response), a phasic pattern (change detection response), and an integrator pattern (cumulative irritation) response. These patterns were modeled quantitatively as the sum of 3 underlying processes. Two time-varying capsaicin stimulus profiles were designed from the quantitative model. In the ascending step paradigm, 30 ppm capsaicin was presented to 42 subjects for 15 minutes, followed immediately and without explanation by 300 ppm capsaicin for 25 minutes. In the descending step paradigm, 300 ppm capsaicin was presented to 36 other subjects for 24 minutes, followed by 10 ppm for 22 minutes. Subjective burn was rated at 1 minute and then at 3-minute intervals throughout the presentation. Fuzzy cluster analysis identified 3 distinct response phenotypes in each paradigm, corresponding to level detection, change detection, and cumulative irritation response patterns identified previously. Discriminant functions permitted classification of these phenotypes from the response patterns. Thus, these paradigms provide the first quantitative phenotypic description of distinct oral pain responses to a common irritant, capsaicin. Perspective This study examined the time-dependent behavior of pain produced by oral application of capsaicin. Three distinct temporal response phenotypes were identified objectively: level detection, change detection, and cumulative irritation detection. These time-dependent analyses provide a new dimension to understanding individual differences in pain sensation in clinical settings.

Gene expression for carbonic anhydrase isoenzymes in human nasal mucosa.

Carbonic anhydrase (CA) is physiologically important in the reversible hydration reaction of CO(2); it is expressed in a number of isoforms (CA I-XIV) with varying degrees of enzymatic activity. In nasal chemesthesis, CA inhibition decreases the electrophysiologic response to CO(2), a common irritant test compound. CA enzymatic activity has been demonstrated in the human nasal mucosa using enzyme histochemical methods, but no systematic study of nasal mucosal CA isoenzyme gene expression has been published. We examined CA gene expression in superficial nasal mucosal scrapings from 15 subjects (6 females; 6 allergic rhinitics; age range, 21-56 years). Both non-quantitative and quantitative reverse transcription polymerase chain reaction (RT-PCR) were performed using primers for each gene coding for the 11 catalytically active CA isoenzymes and the housekeeping gene GADPH. Amplification products of GADPH and 10 of the 11 CA genes were detected in the specimens (CA VA was not detected). Relative expression of the CA genes was quantified using real-time PCR. Averaged across subjects, the relative abundance of the CA isoenzyme transcripts is as follows: CA XII > CA II > CA VB > CA IV > CA IX > CA III > CA XIV > CA I > CA VI > CA VII. Limited qualitative validation of gene expression was obtained by immunohistochemistry for CA I, CA II and CA IV. We also observed inter-individual variability in the expression of CA isoenzymes in human nasal mucosa, potentially contributing to differences in nasal chemosensitivity to CO(2) between individuals