Research statistics in Atopic Eczema: what disease is this?
© Hon et al; licensee BioMed Central Ltd. 2012
Received: 18 January 2012
Accepted: 9 June 2012
Published: 9 June 2012
Atopic eczema is a common and distressing disease. This study aims to review PubMed indexed research statistics on atopic eczema over a-10 year period to investigate the clinical relevance and research interest about this disease.
PubMed (a service of the U.S. National Library of Medicine) was searched for the terms “atopic dermatitis” and “eczema”, with limits activated (Humans, Clinical Trial, Meta-Analysis, Randomized Controlled Trial, English, published in the last 10 years), and editorials, letters, practice guidelines, reviews, and animal studies excluded. Journal impact factor (IF) is in accordance with Journal Citation Report (JCR) 2009, a product of Thomson ISI (Institute for Scientific Information).
A total of 890 articles were retrieved. Taking out publications that were irrelevant and those without an impact factor, 729 articles were obtained. These articles were grouped into dermatology (n = 337, mean IF: 3.01), allergy/immunology (n = 215, mean IF: 4.89), pediatrics (n = 118, mean IF: 2.53) and miscellaneous subject categories (n = 142, mean IF: 5.10). The impact factors were highest in the miscellaneous category (p = 0.0001), which includes such prestigious journals as the New England journal of Medicine (n = 1, IF: 47.05), the Lancet (n = 4, IF: 30.76) and BMJ (n = 6, IF: 13.66). There was no publication in any family medicine or general practice journal. The British Journal of Dermatology (n = 78), Pediatric Allergy and Immunology (n = 49) and Journal of Allergy and Clinical Immunology (n = 46) had the highest number of publications on the subject. Atopic eczema ranked higher in impact factors in allergy/immunology although more publications appeared in the dermatology category.
Atopic eczema is a multidisciplinary disease. Its clinical relevance and research interests are definitely beyond that of a mere cutaneous disease. Investigators may consider allergy/immunology and miscellaneous journal categories for higher impact of their research.
Childhood eczema is a distressing disease associated with atopy[1–6]. Disease onset is usually before 5 years of age in the majority of patients[2, 7]. The presence of atopy, according to the theory of Atopic March, implies that young children with eczema may develop airway allergy such as asthma or allergic rhinitis later in life[5, 6, 8]. Atopy is defined clinically (personal or family history of eczema, asthma or allergic rhinitis) and by laboratory tests (such as positive skin prick reaction to common food and aeroallergens or elevated serum IgE levels above laboratory reference range for age)[4, 9–11]. This study aims to review PubMed-indexed research publications statistics on atopic eczema over a-10 year period to investigate the clinical relevance and research interests about this disease.
PubMed (a service of the U.S. National Library of Medicine) was searched for the terms “atopic dermatitis” and “eczema”, with limits activated (Humans, Clinical Trial, Meta-Analysis, Randomized Controlled Trial, English, published in the last 10 years), and editorials, letters, practice guidelines, reviews, and animal studies excluded. These limits were set so that the data could be manageable. Journal impact factor (IF) is in accordance with Journal Citation Report (JCR) 2009, a product of Thomson ISI (Institute for Scientific Information). Data was expressed as mean and standard deviation (SD) unless otherwise stated. ANOVA was used to compare means. All comparisons were made two-tailed, and p-values less than 0.05 were considered to be statistically significant.
Number of publications in the three subject categories and their impact factors
Number of publications
British Journal of Dermatology
Journal of the American Academy of Dermatology
Skin Pharmacol Physiol
Acta Dermatovenerologica Croatica
American Journal of Clinical Dermatology
Archives of Dermatology
Australasian Journal of Dermatology
Clinical and Experimetnal Dermatology
European Journal of Dermatology
Indian Journal of Dermatol Venereol Leprol
International Journal of Dermatology
Journal of Cutaneous Medicine and Surgery
Journal of Dermatological Science
Journal of Dermatology
Journal of Dermatologic Treatment
Journal der Deutschen Dermatologischen Gesellschaft
Journal of European Acad Dermatol Venereol
Journal of Investigative Dermatology
Photodermatol Photoimmunol Photomed.
Skin Research and Technology
Pediatric Allergy and Immunology
Journal of Allergy & Clinical Immunology
Allergy and Asthma Proceedings
Annals of Allergy Asthma & Immunology
Clinical and Expierimental Allergy
Genes and Immunity
Clinical and Experimental Immunology
International Arch Allergy & Immunology
Journal of Clinical Immunology
Journal of Investigational Allergology & Clinical Immunology
FEMS Immunology and Medical Microbiology
International Journal of Immunopathology & Pharmacology
Seminars in Immunopathology
Allergol Immunopathol (Madr).
Pediatric Allergy and Immunology
International Journal of Pediatr Otolaryngol
Paediatr Perinat Epidemiol
Pediatr Infect Disease Journal
Arch Dis Child
Arch Pediatr Adolesc Medicine
European Journal of Pediatrics
Journal of Paediatrics and Child Health
Journal of Pediatrics (Rio J)
Journal of Pediatric Gastroenterology & Nutrition
Journal of Pediatric Hematology and Oncology
Journal of Pediatrics
Journal of Tropical Pediatrics
World Journal of Pediatrics
Indexed publications with impact factors
IF [mean (SD)]*
Eight publications were under psychiatry/psychology: Psychotherapy and Psychosomatics (n = 1), Psychosomatic Medicine (n = 3), The Journal of Behavioral Medicine (n = 1) and Journal of Psychosomatic Research (n = 3). Five publications were under integrative and complementary medicine: Complementary Therapies in Medicine (n = 2), American Journal of Chinese Medicine (n = 2), Journal of Alternative and Complement Medicine (n = 2) and Journal of Ethnopharmacology (n = 1). There was no publication in any family medicine or general practice journal. The British Journal of Dermatology (n = 78), Pediatric Allergy and Immunology (n = 49) and Journal of Allergy and Clinical Immunology (n = 46) had the highest number of publications on the subject. Atopic eczema ranked higher in impact factors in allergy/immunology although more publications appeared in the dermatology category.
Childhood eczema is a common chronic relapsing disease[1, 2, 12] The theory of “atopic march” views eczema as a systemic atopic disease with skin manifestation in early childhood, and subsequent airway manifestations[2, 5, 8, 11]. Our study of more than seven hundred articles published over a ten-year period showed that eczema is a clinical entity with diverse research interests. Although dermatology journals rank top in number, allergy and medicine journals have higher impact factors and reflect higher research interests and priority. There are also publications in the top medical journals with impact factors above 30, such as the New England Journal of Medicine and the Lancet. In many Asian cities, herbal medicine is extensively sought after by many parents and patients in preference to western medicine. The scope is disproportionately represented by only few articles in the complementary medicine category. Eczema contributes a heavy work load for general practitioners. Surprisingly, no publications were represented in the family medicine categories.
The limitations of this study are that many advances in basic research are not represented due to selection bias of only clinical categories. For instance, filaggrin and related genome wide studies are published in top science journals in recent years[15–17]. The number of articles would be doubled if articles in non-English journals were also included, which was especially true for the complementary medicine category. The number of journals included would certainly increase if a longer study period, say 20 years, is included. With the search limits, “case reports” are also included, which tend to be cited less often than randomized controlled trials and meta-analyses. As such, journals that publish mainly or only randomized controlled trials tend to have higher impact factors.
In dermatology, the “brick-and-mortar hypothesis” states the stratum corneum (the outermost layer of the epidermis) normally consists of fully differentiated corneocytes surrounded by a lipid-rich matrix containing cholesterol, free fatty acids, and ceramide; the structure of this matrix closely resembles that of bricks and mortar in a wall. In eczema, lipid metabolism is abnormal, causing a deficiency of ceramide that leads to transepidermal water loss[18–20]. The underlying genetic deficit might be due to null mutation in the filaggrin gene. Treatment of eczema is primarily with emollient and topical steroid/immunomodulating agent usage. On the contrary, the theory of “Atopic March” favors the consideration of eczema as a systemic disease, and indicates that many children with atopic eczema go on to develop asthma and allergic rhinitis as their eczema improves with time[5, 6, 8]. Nitric oxide (NO) has been shown to be a marker of airway inflammation. Study has shown levels of NO in exhaled breath condensate are higher in children with eczema without asthma, and may indicate a predictive role of exhaled NO for the development of asthma. Atopic eczema has long been considered as a disease primarily driven by the immune system. Eosinophils and monocytes are known for modulating allergic symptoms. Eosinophilia with enhanced eosinophil survival and elevated eosinophil granule proteins have been detected in AD patients. Overactive monocytes increase the production of prostaglandin E and IL-10, which alter the balance between Th1 and Th2 functional responses. This accounts for many atopic features present in eczema patients, including elevated IL-4, 5 and 6 productions by T cell, increased IgE synthesis, reduced IFN-γ production and impaired cell-mediated immune response. The “hygiene hypothesis” further explains the skewing of immune system towards Th2 profile. Initial atopic sensitization is thought to take place in utero where transplacental allergen elicits Th2 response of fetal lymphocytes. After delivery, while healthy infants switch their Th2 to Th1 profile by stimulation of infectious agents, this reversal does not occur in atopic individuals. Their immunological reaction still favors the Th2 type which reacts to stimulants and results in allergic disease. Smaller family, improved hygienic strategies, antibiotic usage etc all lead to reduction of surrounding microbes and supports this development.
In oriental medicine principles, eczema is considered as a systemic disease with imbalances of Qi or internal energy. Many Asian patients would think that western medicine cannot offer a cure, and that topical steroids and associated treatment have significant side effects. These principles all favor the concept that eczema is more like a systemic disease (atopy) with early skin manifestations (dermatitis) than a skin disease with systemic associations. Recent research suggested that neutrophils, lymphocytes, eosinophils, immunoglobulins and complements are all important players in the pathophysiology of eczema. It follows that treating eczema as a primary dermatological disease with only topical armamentarium without considering managing this complicated disease with a systemic and holistic approach is bound to meet with suboptimal effects. Its clinical relevance and research interests are definitely beyond that of a mere cutaneous disease.
- Carroll CL, Balkrishnan R, Feldman SR, Fleischer AB, Manuel JC: The burden of atopic dermatitis: impact on the patient, family, and society. Pediatr Dermatol. 2005, 22: 192-199. 10.1111/j.1525-1470.2005.22303.x.View ArticlePubMedGoogle Scholar
- Leung AK, Hon KL, Robson WL: Atopic dermatitis. Adv Pediatr. 2007, 54: 241-273. 10.1016/j.yapd.2007.03.013.View ArticlePubMedGoogle Scholar
- Lewis-Jones S, Mugglestone MA: Guideline Development Group. Management of atopic eczema in children aged up to 12 years: summary of NICE guidance. BMJ. 2007, 335: 1263-1264. 10.1136/bmj.39405.503773.AD.PubMed CentralView ArticlePubMedGoogle Scholar
- Hon KL, Tsang S: Atopy in children with eczema. Indian J Pediatr. 2010, 77: 519-522. 10.1007/s12098-010-0042-0.View ArticlePubMedGoogle Scholar
- Spergel JM: From atopic dermatitis to asthma: the atopic march. Ann Allergy Asthma Immunol. 2010, 105: 99-106. 10.1016/j.anai.2009.10.002.View ArticlePubMedGoogle Scholar
- Hon KL, Wang SS, Leung TF: The atopic march: from skin to the airways. Iran J Allergy, Asthma Immunol. 2012, 11: 73-77.Google Scholar
- Williams HC, Johansson SG: Two types of eczema–or are there?. Journal of Allergy & Clinical Immunology. 2005, 116: 1064-1066. 10.1016/j.jaci.2005.08.026.View ArticleGoogle Scholar
- Spergel JM, Paller AS: Atopic dermatitis and the atopic march. Journal of Allergy & Clinical Im. 2003, 112: S118-S127.View ArticleGoogle Scholar
- Johansson SG, Hourihane JO, Bousquet J: A revised nomenclature for allergy. An EAACI position statement from the EAACI nomenclature task force. Allergy. 2001, 56: 813-824. 10.1034/j.1398-9995.2001.t01-1-00001.x.View ArticlePubMedGoogle Scholar
- Hon KL, Lam MC, Leung TF: Are age-specific high serum IgE levels associated with worse symptomatology in children with atopic dermatitis?. Int J Dermatol. 2007, 46: 1258-1262. 10.1111/j.1365-4632.2007.03407.x.View ArticlePubMedGoogle Scholar
- Hon KL: Patterns of food and aeroallergen sensitization in childhood eczema. Acta Paediatrica. 2008, 97: 1734-1737. 10.1111/j.1651-2227.2008.01034.x.View ArticlePubMedGoogle Scholar
- Emerson RM, Williams HC, Allen BR: Severity distribution of atopic dermatitis in the community and its relationship to secondary referral. Br J Dermatol. 1998, 139: 73-76. 10.1046/j.1365-2133.1998.02316.x.View ArticlePubMedGoogle Scholar
- Hon KL, Ma KC, Wong Y, Leung TF, Fok TF: A survey of traditional Chinese medicine use in children with atopic dermatitis attending a paediatric dermatology clinic. J Dermatol Treat. 2005, 16: 154-157. 10.1080/09546630510038938.View ArticleGoogle Scholar
- Hon KL, Chan BC, Leung PC: Chinese herbal medicine research in eczema treatment. Chinesische Medizin. 2011, 6: 17-Google Scholar
- Palmer CN, Irvine AD, Terron-Kwiatkowski A: Common loss-of-function variants of the epidermal barrier protein filaggrin are a major predisposing factor for atopic dermatitis. Nat Genet. 2006, 38: 441-446. 10.1038/ng1767.View ArticlePubMedGoogle Scholar
- Palmer CN, Ismail T, Lee SP: Filaggrin null mutations are associated with increased asthma severity in children and young adults. Journal of Allergy & Clinical Immunology. 2007, 120: 64-68. 10.1016/j.jaci.2007.04.001.View ArticleGoogle Scholar
- Sandilands A, Terron-Kwiatkowski A, Hull PR: Comprehensive analysis of the gene encoding filaggrin uncovers prevalent and rare mutations in ichthyosis vulgaris and atopic eczema. Nat Genet. 2007, 39: 650-654. 10.1038/ng2020.View ArticlePubMedGoogle Scholar
- Chamlin SL, Kao J, Frieden IJ: Ceramide-dominant barrier repair lipids alleviate childhood atopic dermatitis: changes in barrier function provide a sensitive indicator of disease activity. J Am Acad Dermatol. 2002, 47: 198-208. 10.1067/mjd.2002.124617.View ArticlePubMedGoogle Scholar
- Maintz L, Novak N: Getting more and more complex: the pathophysiology of atopic eczema. Eur J Dermatol. 2007, 17: 267-283.PubMedGoogle Scholar
- Sehra S, Tuana FM, Holbreich M: Scratching the surface: towards understanding the pathogenesis of atopic dermatitis. Crit Rev Immunol. 2008, 28: 15-43. 10.1615/CritRevImmunol.v28.i1.20.View ArticlePubMedGoogle Scholar
- Zinelli C, Caffarelli C, Strid J, Jaffe A, Atherton DJ: Measurement of nitric oxide and 8-isoprostane in exhaled breath of children with atopic eczema. Clin Exp Dermatol. 2009, 34: 607-612. 10.1111/j.1365-2230.2008.03142.x.View ArticlePubMedGoogle Scholar
- Strachan DP: Family size, infection and atopy: the first decade of the "hygiene hypothesis". Thorax. 2000, 55 (Suppl 1): S2-S10.PubMed CentralView ArticlePubMedGoogle Scholar
- Rautava S, Ruuskanen O, Ouwehand A, Salminen S, Isolauri E: The hygiene hypothesis of atopic disease–an extended version. J Pediatr Gastroenterol Nutr. 2004, 38: 378-388. 10.1097/00005176-200404000-00004.View ArticlePubMedGoogle Scholar
- Hon K, Leung TF: Seromarkers in childhood atopic dermatitis. Expert Rev Dermatol. 2010, 5: 299-314. 10.1586/edm.10.21.View ArticleGoogle Scholar
- Hon KL, Wang SS, Pong H, Leung TF: Circulating immunoglobulins, leucocytes and complements are players in childhood-onset atopic eczema. Indian J Pediatr. In pressGoogle Scholar
- Hon KL, Wang SS, Lau Z: Pseudoceramide for childhood eczema: does it work?. Hong Kong Medical Journal. 2011, 17: 132-136.PubMedGoogle Scholar
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