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C O N T A C T D E R M A T I T I S A N D A L L E R G Y D O I 1 0 . 1 1 1 1 / j . 1 3 6 5 - 2 1 3 3 . 2 0 0 5 . 0 6 8 4 5 . x Allergic contact dermatitis in children: should pattern ofdermatitis determine referral? A retrospective study of 500children tested between 1995 and 2004 in one U.K. centreT.H. Clayton, S.M. Wilkinson, C. Rawcliffe,* B. Pollock and S.M. Clark Department of Dermatology, Leeds General Infirmary, Leeds LS1 3EX, U.K.
*Clinical Trials Unit, Leeds Foundation for Dermatological Research, Leeds LS1 3EX, U.K.
Background Allergic contact dermatitis (ACD) increases with age, and a prevalence of between 13Æ3% and 24Æ5% has been reported. Patch testing infants may be particularly difficult, and false-positive reactions may occur.
Objectives The purpose of this retrospective study was to determine whether the site of primary dermatitis in children could predict a diagnosis of ACD. The cur- rent frequency of sensitization in children was also evaluated and the main sensi-tizing substances among children were verified.
Methods Between 1995 and 2004, 500 children were patch tested and entered on allergic contact dermatitis, children, site of to the patch test database at Leeds General Infirmary. Analysis of the database included identifying the presenting patterns of eczema and reviewing the patch Results Of the children, 133 (27%) had one or more positive patch test result.
The effect of age on the likelihood of a positive patch test was highly significant(P < 0Æ001). Girls were significantly more likely to have a positive patch testcompared with boys: odds ratio for a positive test 0Æ62 (95% confidence interval0Æ41–0Æ95; P ¼ 0Æ029). Type IV allergy to nickel (33%) was the most frequentfinding. Reactions to fragrance mix (18%), cobalt (11%), mercapto chemicals,Myroxylon pereirae and p-phenylenediamine (each 8%) were the next most common.
No statistical significance was found in the relationship between the site of pri-mary dermatosis and a positive patch test result.
Conclusions The pattern of presenting dermatitis in children should not determinereferral for patch testing. Any child with persistent eczema should be referred forpatch testing.
Allergic contact dermatitis (ACD) is known to increase with of primary dermatoses are more likely to result in positive age. It is felt to be less common in children under 10 years, patch test results. The primary objective of this study was to although recent reports suggest that the rates of sensitization investigate whether the site of primary dermatosis predicted in children may be higher than was previously thought.1–3 positive reactions. The current frequency of sensitization in Children and infants mount a normal immunological response children was also evaluated, and the main sensitizing sub- to allergens. The prevalence of ACD in children has been stances among children were verified. This retrospective analy- reported at between 13Æ3% and 24Æ5% in several cross-sec- sis represents the largest study of ACD in children in the U.K.
tional studies.4 Patch testing in children is technically more difficult to undertake than in adults. Children’s skin maybecome more easily irritated and this could result in an increased number of false-positive reactions. Some authorshave recommended reduced standard allergen series.5 The ana- A total of 500 patients underwent patch testing in the Contact tomical site of primary dermatosis may point to the eliciting Dermatitis Investigation Unit at Leeds General Infirmary allergen source, e.g. foot dermatitis in children may be caused between 1995 and 2004. All patient details and patch test by sensitization to rubber chemicals found in modern foot- results were routinely prospectively recorded on the depart- wear. There have been no studies looking at whether patterns mental patch test database. The children were identified from Ó 2005 British Association of Dermatologists • British Journal of Dermatology 2006 154, pp114–117 Allergic contact dermatitis in children, T.H. Clayton et al. 115 the patch test database. The patch test results and diagnoses Logistic curve- Predicted P(Y= Positive test) by Age All children were patch tested to the British Contact DermatitisSociety standard series, with additional series added whereimplicated from history. Allergens were applied to healthyskin on the patients’ backs under Finn Chambers aluminium Norway), and left for 48 h. Readings were undertaken at48 h and 96 h. Reactions were scored according to the criteria of the International Contact Dermatitis Research Group.6 Fig 1. Logistical regression for age and positive patch test result.
The v2 test was used for preliminary analysis of sensitizationto allergens and site of primary dermatosis. Logistic regression analysis was used to elucidate the relationship between ageand a positive patch test result. Analysis was carried out usingStataÒ software, version 6 (Stata Corp., College Station, TX,U.S.A.).
During the study period 500 children were referred to theDepartment of Dermatology, Leeds General Infirmary for patchtest investigations. Of these, 133 (27%) had one or more pos- itive patch test result. The mean ± SD age of patients with a positive test was 12 ± 3Æ8 years (median 13, range 0–16).
This was significantly higher than that of patients who had a Fig 2. The relationship between age and a positive patch test reaction negative result (mean ± SD 10 ± 4Æ5 years, median 11, range 0–16) (P ¼ 0Æ0001; Mann–Whitney U-test; Table 1). Theeffect of age on the likelihood of a positive patch test was In the 133 children who had a positive reaction, 61% of highly significant (P < 0Æ001), a finding consistent with the reactions were considered to be of current clinical relevance.
conclusion that older patients are more likely to have a posit- Nickel sulphate was the most frequent positive test with a total ive reaction. The odds ratio for a positive test for two patients number of 44 reactions (33%), although it was found to be separated by 1 year in age was 1Æ1 [95% confidence interval relevant in only three cases. The next most common reactions (CI) 1Æ05–1Æ7]; the older patient was at greater risk of a posit- were to fragrance mix (24 reactions; 18%), cobalt (15 reac- ive patch test (Figs 1 and 2). Girls were significantly more tions; 11%), mercapto chemicals (11 reactions; 8%), p-pheny- likely to have a positive patch test compared with boys: odds lenediamine (PPD) (11 reactions; 8%), Myroxylon pereirae ratio for a positive test 0Æ62 (95% CI 0Æ41–0Æ95; P ¼ 0Æ029).
(balsam of Peru) (11 reactions; 8%), colophony (nine Table 1 Results of patch testing in 500 children Ó 2005 British Association of Dermatologists • British Journal of Dermatology 2006 154, pp114–117 116 Allergic contact dermatitis in children, T.H. Clayton et al.
Table 2 Most frequent type IV reactions in children 1995–2004 tattoos in the 5–10-year age group and hair dye in the 10–16-year age group. Of the children with positive reactions a personal history of atopy was found in 81 of 133 (61%), and 55 children (41%) had a diagnosis of atopic dermatitis (AD).
When the results were stratified for site of dermatosis (Table 3), the palm of the hand (33%) was the most frequent primary body site to result in positive reactions, followed by the sole of the foot (29%) and the leg (29%). No statistical significance was found in the relationship between the site of primary dermatosis and a positive patch test result. There were no positive reactions detected in any of the children who had been referred with a clinical diagnosis of either napkin derma- titis or perianal dermatitis. However, this number was low (n ¼ 8) and not statistically significant. The mercapto chemi- cals accounted for 61Æ5% of all positive reactions in children referred with a diagnosis of plantar dermatitis. This was found to be a statistically significant association (P < 0Æ005).
This retrospective study represents, to date, the largest U.K.
study of contact dermatitis in children. There have been sev- eral retrospective studies of children with ACD in the litera- ture, with a reported prevalence ranging between 13Æ3% and 24Æ5%.1–3 The results from this study are in concordance withthese studies. ACD acquired in childhood has important reper- reactions; 7%) and wool alcohols (eight reactions; 6%) cussions for patients and may affect decisions regarding future (Table 2). PPD allergy was detected only in children over occupation in adulthood. ACD is an eczematous skin disease 5 years. The most common sources of PPD allergy were henna mediated by a type IV immune mechanism, involving Table 3 The most frequent sites of primarydermatoses and the patch test result Ó 2005 British Association of Dermatologists • British Journal of Dermatology 2006 154, pp114–117 Allergic contact dermatitis in children, T.H. Clayton et al. 117 T lymphocytes. Patch testing is the current standard evidence- sources of PPD allergy in this study in children aged 5–10 years.
based approach for identifying sensitizing allergens.7 The diag- In older children hair dye was the most common sensitizer.
nosis of ACD in children is based solely on the finding of a The relationship between atopy and ACD is poorly under- stood. Whether patients with AD are more prone to ACD than The objective of this study was to assess whether the pre- nonatopic individuals remains controversial. Recent studies senting pattern of dermatitis could predict the outcome of the have indicated that there is a similar prevalence of ACD in patch test alone. However, no correlation could be found patients with AD and nonatopics.7 There has been evidence to between the presenting pattern of dermatosis and a positive support lower rates of ACD in atopics.12 A higher rate of patch test. The lack of any predictive values for the pattern of false-positive reactions has been reported in atopic individu- the primary dermatosis clearly stresses the need for underta- als.13 Irritancy is increased in patients with chronic dermatitis king the investigation in any child with a persistent eczema.
and the frequency of irritant reactions has been shown to cor- Irritant napkin dermatitis is the most prevalent form of nap- relate both with greater numbers of ACD responses and with kin dermatitis;8 this was reflected by the fact that none of the presence of atopy.14 Our study showed an increased preval- children referred for patch testing with this diagnosis had a ence of contact allergy in children with AD. This may be due positive result. Allergic contact napkin dermatitis may compli- to the damaged epidermal barrier found in AD, with sub- cate any type of napkin rash. Sensitization can develop to cer- sequent increased penetration of allergens or, alternatively, tain topical medicaments, such as topical antifungals and children with AD are exposed to more sensitizers as a result of antibiotics. However, in most cases napkin rashes are irritant the topical treatments that they may be using for their disease.
in their aetiology and further investigations are not required.
Furthermore, our results may have occurred because of selec- Bacterial infection of the perianal skin may be misdiagnosed tion bias (a specialized patch test clinic), and may not reflect as napkin dermatitis. Perianal dermatitis occurs more com- patterns of ACD seen in an unselected population.
monly in boys aged between 3 and 4 years and is usually In summary, this study found no significant correlation caused by group A b-haemolytic streptococci.9 None of the between the presenting pattern of eczema and a subsequent children with a diagnosis of perianal dermatitis referred for positive patch test. The pattern of presenting dermatitis in chil- patch testing in this study had positive reactions.
dren should not determine referral for patch testing. Any child Juvenile plantar dermatitis (JPD) is an inflammatory derma- with persistent eczema should be referred for patch testing.
tosis that affects the anterior portion of the undersurface ofthe feet in children under 15 years. Its pathogenesis is poorly understood and it tends to occur more frequently in winter.10JPD is exacerbated by occlusive footwear such as sports shoes 1 Seidenari S, Giusti F, Pepe P, Mantovani L. Contact sensitization in with rubber soles and synthetic socks, and it occurs more 1094 children undergoing patch testing over a 7-year period. Pedi-atr Dermatol 2005; 22:1–5.
commonly in boys. This study found a strong positive correla- 2 Ferna´ndez Vozmediano JM, Armario Hita JC. Allergic contact der- tion between sensitization to mercapto-rubber chemicals and a matitis in children. J Eur Acad Dermatol Venereol 2005; 19:42–6.
clinical diagnosis of plantar dermatitis. Furthermore, children 3 Lewis VJ, Statham BN, Chowdhury MM. Allergic contact dermatitis who avoid culprit sensitizing agents show improvement in in 191 consecutively patch tested children. Contact Dermatitis 2004; their clinical condition. This emphasizes the need to patch test 4 Mortz CG, Andersen KE. Allergic contact dermatitis in children and This study also confirmed the notion that ACD increases adolescents. Contact Dermatitis 1999; 41:121–30.
5 Hjorth N. Contact dermatitis in children. Acta Derm Venereol (Stockh) with age. In this study girls were significantly more likely to have positive tests at any age. This finding is consistent with 6 Wilkinson DS, Fregert S, Magnusson B et al. Terminology of con- previously published studies.2,4 The most common allergens tact dermatitis. Acta Derm Venereol (Stockh) 1970; 50:287–92.
found in this study were similar to those found in other stud- 7 Vender RB. The utility of patch testing children with atopic derma- ies, namely nickel sulphate and fragrance.
titis. Skin Ther Lett 2002; 7:4–6.
Ear piercing appears to be an important cause for nickel 8 Atherton DJ. A review of the pathophysiology, prevention and treat- allergy. Girls are more likely to have their ears pierced and this ment of irritant diaper dermatitis. Curr Med Res Opin 2004; 20:645–9.
9 Herbst R. Perineal streptococcal dermatitis ⁄ disease: recognition and was reflected in the results for positive tests to nickel. Fragrance management. Am J Clin Dermatol 2003; 4:555–60.
allergy in children may be due to the increased production of 10 Harper J, Oranje A, Prose N. Juvenile plantar dermatosis. In: Text- perfumed products made specifically for children. Young chil- book of Pediatric Dermatology. Oxford: Blackwell Science, 2000; 284–6.
dren may ‘play’ with cosmetics and girls are more likely to wear 11 Baron S, Baxter K, Wilkinson M. Allergic contact dermatitis to perfumed cosmetics and hair products. An increase in PPD henna tattoo. Arch Dis Child 2003; 88:747.
allergy has recently been reported in children. They may 12 Rystedt I. Atopic background in patients with occupational hand develop sensitization after a PPD-adulterated henna tatoo.11 eczema. Contact Dermatitis 1985; 12:247–54.
13 Lammintausta K, Kalimo K, Fagerlund VL. Patch test reaction in Holiday henna tattoos are becoming increasingly fashionable atopic dermatitis. Contact Dermatitis 1992; 26:234–40.
and parents should be advised that the darker paints often con- 14 Klas PA, Corey G, Storrs FJ et al. Allergic and irritant patch test tain PPD. PPD allergy was found only in children over 5 years reactions and atopic disease. Contact Dermatitis 1996; 34:121–4.
in this study. Indeed, henna tattoos were the most common Ó 2005 British Association of Dermatologists • British Journal of Dermatology 2006 154, pp114–117

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