Effect of photoaging on skin test response to histamine independent of chronologic age.

BACKGROUND: Skin prick-puncture test responses to histamine on the upper back and forearms in older individuals are frequently small or absent but are often present or larger when repeated on the lower back. OBJECTIVE: To determine whether photoaging or natural aging causes a smaller response to a prick-puncture skin test. METHODS: Prick-puncture skin tests to histamine were performed on sun-exposed and sun-protected areas in younger (n = 61, aged 20-50 years) and older (n = 63, aged 60-87 years) adult volunteers. The skin was scored for photoaging by physical examination, and coloration was measured by a colorimeter. RESULTS: Large variation of photoaging occurred within age groups. Histamine wheals and flare were not different between the 2 age groups, but those adults with the greatest photoaging had smaller histamine wheals and flare on the upper back, with a trend for smaller flares on the volar aspect of the forearms and lower back. There was marked variability in response to histamine within individual adults, depending on the locale of the tests. CONCLUSION: Photoaging, but not age alone, is associated with a smaller response to histamine in sun-exposed areas. Before prick-puncture skin tests are performed, the skin should be examined for sun damage, and a sun-protected area should be selected; in vitro allergy testing may be substituted if there is no sun-protected skin area.

Asthma in the elderly: Current understanding and future research needs--a report of a National Institute on Aging (NIA) workshop.

Asthma in the elderly is underdiagnosed and undertreated, and there is a paucity of knowledge on the subject. The National Institute on Aging convened this workshop to identify what is known and what gaps in knowledge remain and suggest research directions needed to improve the understanding and care of asthma in the elderly. Asthma presenting at an advanced age often has similar clinical and physiologic consequences as seen with younger patients, but comorbid illnesses and the psychosocial effects of aging might affect the diagnosis, clinical presentation, and care of asthma in this population. At least 2 phenotypes exist among elderly patients with asthma; those with longstanding asthma have more severe airflow limitation and less complete reversibility than those with late-onset asthma. Many challenges exist in the recognition and treatment of asthma in the elderly. Furthermore, the pathophysiologic mechanisms of asthma in the elderly are likely to be different from those seen in young asthmatic patients, and these differences might influence the clinical course and outcomes of asthma in this population.

Prick puncture skin tests and serum specific IgE as predictors of nasal challenge response to dermatophagoides pteronyssinus in older adults.

BACKGROUND: The ability of prick puncture skin test (PPST) results and the presence of serum specific IgE (sIgE) to Dermatophagoides pteronyssinus to predict positive or negative nasal challenge (NC) results has not been determined in older adults. OBJECTIVE: To determine if allergy skin test and/or serum sIgE is diagnostic of allergic rhinitis in older adults. METHODS: Forty-eight adults (20 younger and 28 older) with rhinitis underwent NC to D. pteronyssinus 1 to 4 weeks after PPST and sIgE to D. pteronyssinus. Patients were not aware of their in vivo or in vitro results at the time of their NC. RESULTS: Fourteen of 48 adults (10 younger and 4 older) were NC positive. The positive predictive values for older adults with positive NC results ranged from 28.57% to 42.86% for PPST and was 16.67% for sIgE. In contrast, positive predictive values in younger adults ranged from 76.92% to 100% for PPST and was 100% for sIgE. However, negative PPST results and sIgE had high predictive values for a negative NC result to D. pteronyssinus in older adults (90.48%-95.24% for PPST and 89.47% for sIgE). CONCLUSIONS: Although PPST and sIgE negative results were good predictors of negative NC outcomes, neither positive PPST results nor serum sIgE to D. pteronyssinus predicted positive NC results in older adults. PPST and sIgE to D. pteronyssinus were excellent predictors of both positive and negative NC outcomes in younger adults.

Serum total IgE and specific IgE to Dermatophagoides pteronyssinus, but not eosinophil cationic protein, are more likely to be elevated in elderly asthmatic patients.

Serum IgE (total and five specific) and eosinophil cationic protein (ECP) levels were compared in elderly physician-diagnosed patients with asthma with non-asthmatic controls matched by age and gender to ascertain whether elevated levels are indicators of asthma in the elderly. All subjects and controls were non-smokers. The subjects were participants in the Florida Geriatric Research Program (FGRP), a longitudinal aging study that tracks the health status of people 65 years and older. Frozen sera from 33 randomly selected asthmatic patients and 21 controls, none of whom had any other chronic respiratory disease, such as chronic obstructive pulmonary disease (COPD), all between the ages of 65 and 90, were assessed for total IgE; five specific IgE concentrations (for cat, ragweed, German cockroach, Dermatophagoides pteronyssinus (Dp) and live oak); and ECP levels using the Pharmacia Unicap System. The odds of an elderly asthmatic patient having a total IgE of > 100 KU/L were higher than that for a non-asthmatic patient (odds ratio (OR) = 13.0; Mantel-Haenszel (MH) p = 0.005). The odds of elderly asthmatic patients having at least one positive serum specific IgE compared to elderly age-matched non-asthmatic patients were higher (OR = 21.2; MH p = 0.001). Among the five specific IgE concentrations, only IgE for Dp was higher in asthmatic than in non-asthmatic patients (OR = 13.00; MH p = 0.005). The ECP level was not significantly different between elderly asthmatic and non-asthmatic patients (asthmatic mean = 20.7 microg/L, SE = 0.48; control mean = 19.5 microg/L. SE = 0.76) (mean for younger adults 4.4 microg/L, Pharmacia Diagnostics). The serum of elderly asthmatic patients is more likely to have elevated total IgE and a positive specific IgE to Dp. ECP is elevated in elderly subjects but is not an indicator of asthma.

Allergen prick-puncture skin testing in the elderly.

Many older patients present with rhinitis, conjunctivitis, asthma or itching that the patient attributes to allergies. Yet physicians often dismiss allergy in the elderly as irrelevant. Testing elderly patients for allergies is sometimes challenging as changes in the skin may cause difficulty in applying skin tests, and the response of the skin may be difficult to measure. The prick puncture skin test is the preferred method of immediate-type allergy testing, but careful examination of the skin prior to skin testing is important. If the area of skin where allergen skin tests are routinely placed is either atrophic or severely sun damaged, a sun-protected area should be sought. If no suitable area of skin can be identified, in vitro allergen testing should be considered. Skin-test results must be interpreted with care in the elderly. Positive skin tests to an allergen must correlate with a history of exacerbation to the allergen. By identifying specific allergens to which the elderly patient is sensitive, avoidance measures or specific allergen vaccination can be recommended, improving the quality of life and decreasing the need for medications.