Onset of chilblains in relation with weather conditions

Chilblains or perniosis is a moderately severe form of cold injury, localized to peripheral parts of the body, which occurs after exposure to non-freezing temperatures and damp conditions. Although inter-individual variations exist with respect to susceptibility to develop chilblains, no study has been carried out in this region to determine the role of different weather conditions either alone or in combination, in predisposing the susceptible individuals to chilblains. The objective of this study was to determine the relationship between weather conditions and onset of chilblains at a moderately cold weather station. This study was conducted at the Department of Dermatology, Combined Military Hospital, Abbottabad, from Dec 2004 to Mar 2005. All patients fulfilling the clinical criteria for diagnosis of chilblains were included in the study. These patients were interviewed and examined thoroughly. A specially designed proforma was filled for each patient separately. Meteorological department was contacted for record of weather conditions. Onset of chilblains in each patient was related with weather conditions of that particular month. Computer programme SPSS 10 was used for statistical analysis. Out of 111 patients, 67 [60.4%] were males and 44 [39.6%] were females. Eighty nine [80.2%], 90 [81.1%] and 90 [81.1%] patients had onset in relation with lower temperature [<10 °C], relatively low atmospheric pressure [<1500 kpa] and higher relative humidity [>60%] respectively. There was statistically significant relationship of weather conditions with onset of chilblains when different groups, i.e., elderly and young, males and females, locals and non locals, outdoor workers and those remaining inside most of the time and those having disease of longer or shorter duration were compared. The cold weather conditions that can be endured by humans depend on combination of the duration and the extent of the exposure, in addition to physiological adaptive changes. However, susceptibility to chilblains increases when ambient temperature is less than 10°C and relative humidity is more than 60%. Elderly, females, outdoor workers and those having chronic or recurrent episodes of chilblains are less tolerant to cold weather and develop the disease under lesser ambient cold

Chilblains at Abbottabad, a moderately cold weather station

Chilblains are quite often seen in various parts, in particular cold weather areas of Pakistan. Unfortunately, no studies have so far been carried out in Pakistan, to determine epidemiological aspects of chilblains. The objective of this study was to see the epidemiological patterns of chilblains at a moderately cold weather station. The study was conducted at Dermatology out patient department of Combined Military Hospital, Abbottabad from 1 Dec 2004 to 31 Mar 2005. All the patients fulfilling clinical criteria for the diagnosis of chilblains were registered. Every patient was interviewed in detail followed by thorough physical examination. Complete Blood Count, Urine Routine Examination and Anti Nuclear Factor were carried out in only those patients, having the disease of more than 3 years duration. A pre-designed proforma was filled separately for each patient. Out of 111 patients, 67 [60.4%] males and 44 [39.6%] females were registered with the diagnosis of chilblains. Fifty nine [53.2%] patients were locals and 52 [46.8%] were non locals. Out door workers were 75 [67.6%]. Onset in majority of the patients [42.3%] was in the age group 11-20 years. Family history of chilblains was present in 25 [22.5%] patients and 8 patients [7.2%] were smokers. The disease of longer duration was more common in females and locals. At moderately cold weather areas, out door workers and young adolescents are more likely to develop Chilblains. The disease of longer duration is more common among females and local residents. On the other hand, first episode or the disease of shorter duration is more common among non locals at moderately cold weather stations because of poor acclimatization and inadequate protection