Can worsening of atopic dermatitis be a symptom of food allergy if the patient does not have other allergy-specific symptoms?
Level of evidence: C
Worsening of atopic dermatitis without other allergy symptoms may be a rare symptom of a food allergy in children.
In two studies of children with suspected food allergy and going through double-blind placebo-controlled food challenge, in total 19/1012(1.9%) in placebo group compared to 113/1744(6.5%) in verum group experienced worsening of atopic dermatitis without other allergy symptoms. This would translate to about 5% of children with food allergy, only reacting with worsening of atopic dermatitis. The study results were inconsistent, which warrants caution in interpretation. In the second study patients with current atopic dermatitis, only 26/272(9.6%) reacted with verum compared to 13/272(4.8%) with placebo by worsening of atopic dermatitis with or without other symptoms.
The studies also reported a risk of worsening atopic dermatitis when having other allergy symptoms. In the placebo group, in total 7/1012(0.7%) and in the verum group 92/1744(5.3%) experienced worsening of atopic dermatitis concurrent with other allergy symptoms. The results suggest that about 5% of patients with food allergy may experience worsening of atopic dermatitis concurrently with other symptoms.
| Reference | Study type | Population | Intervention and comparison | Outcomes | Risk of bias |
|---|---|---|---|---|---|
| RCT=randomized controlled trial; SR=systematic review; MA=meta-analysis; DBPCFC= double-blind, placebo-controlled food challenge; AD=atopic dermatitis | |||||
| «Ahrens B, Niggemann B, Wahn U, ym. Positive reactions to placebo in children undergoing double-blind, placebo-controlled food challenge. Clin Exp Allergy 2014;44(4):572-8 »1 | Cohort | 639 Caucasian children with suspected food allergy. | DBPCFC; 740 placebo challenges and 1472 verum food challenges with cow's milk (n 556), hen's egg (n 387), soy (n 263), wheat (n 240), peanut (n 17), and hazelnut (n 9). Food allergy prevalence about 49%. Challenge blocks of placebo or verum on two different days in a randomized order. | Worsening of atopic eczema within 24 hours after the challenge. | High |
| «Roerdink EM, Flokstra-de Blok BM, Blok JL, ym. Association of food allergy and atopic dermatitis exacerbations. Ann Allergy Asthma Immunol 2016;116(4):334-8 »2 | Cohort | 317 children with current atopic dermatitis, and suspected food allergy. | Clinical reactions in 272 patients with AD. All patients went through both verum and placebo challenges in randomized order. At least 2 weeks between the challenges. Food allergy prevalence 52.1%. | Exacerbation of AD during placebo vs. verum food challenge within 48 hours after the challenge. | High |
| Reference | Comments |
|---|---|
| «Ahrens B, Niggemann B, Wahn U, ym. Positive reactions to placebo in children undergoing double-blind, placebo-controlled food challenge. Clin Exp Allergy 2014;44(4):572-8 »1 | Double-blind placebo controlled-food challenges. Blinding of analysts not reported. Children could have either two of the same challenge (placebo or verum) or both or just one in some cases, in randomized order. Retrospective analysis. |
| «Roerdink EM, Flokstra-de Blok BM, Blok JL, ym. Association of food allergy and atopic dermatitis exacerbations. Ann Allergy Asthma Immunol 2016;116(4):334-8 »2 | Double-blind placebo controlled-food challenges. Missing data from 14% of the participants. Retrospective analysis. Late reactions were ascertained by semistructured telephone interviews. |
Results
| Reference | Number of challerges placebo/verum | Follow-up time | Absolute number of events (%) during placebo | Absolute number of events (%) during verum | Relative risk (95% CI) |
|---|---|---|---|---|---|
| I= intervention; C=comparison; CI=confidence interval; RR=Relative risk; AD=atopic dermatitis | |||||
| «Ahrens B, Niggemann B, Wahn U, ym. Positive reactions to placebo in children undergoing double-blind, placebo-controlled food challenge. Clin Exp Allergy 2014;44(4):572-8 »1 | 740/1472 | 24 h | 12/740 (1.6%) | 105/1472 (7.1%) | 4.40 (2.44-7.94) |
| «Roerdink EM, Flokstra-de Blok BM, Blok JL, ym. Association of food allergy and atopic dermatitis exacerbations. Ann Allergy Asthma Immunol 2016;116(4):334-8 »2 | 272/272 | 48 h | 7/272 (2.6%) | 8/272 (2.9%) | 1.14 (0.42-3.1) |
| Risk ratios were not reported but calculated by the original studies from the absolute numbers. Level of evidence: low The quality of evidence is downgraded due to risk of bias and inconsistency. | |||||
| Reference | Number of challenges placebo/verum | Follow-up time | Absolute number of events (%) during placebo | Absolute number of events (%) during verum | Relative risk (95% CI) |
|---|---|---|---|---|---|
| I= intervention; C=comparison; CI=confidence interval; RR=Relative risks; AD=atopic dermatitis | |||||
| «Ahrens B, Niggemann B, Wahn U, ym. Positive reactions to placebo in children undergoing double-blind, placebo-controlled food challenge. Clin Exp Allergy 2014;44(4):572-8 »1 | 21/725 | 24 h | 1/740 (0.1%) | 74/1472 (5.0%) | 37.2 (5.2-267.1) |
| «Ahrens B, Niggemann B, Wahn U, ym. Positive reactions to placebo in children undergoing double-blind, placebo-controlled food challenge. Clin Exp Allergy 2014;44(4):572-8 »1 | 272/272* | 48 h | 6/272 (1.5%) | 18/272 (6.6%) | 3.0 (1.2-7.44) |
| Risk ratios were not reported by the original studies but calculated from the absolute numbers. Level of evidence: moderate The quality of evidence is downgraded due to risk of bias. | |||||
References
- Ahrens B, Niggemann B, Wahn U, ym. Positive reactions to placebo in children undergoing double-blind, placebo-controlled food challenge. Clin Exp Allergy 2014;44(4):572-8 «PMID: 24479560»PubMed
- Roerdink EM, Flokstra-de Blok BM, Blok JL, ym. Association of food allergy and atopic dermatitis exacerbations. Ann Allergy Asthma Immunol 2016;116(4):334-8 «PMID: 26947239»PubMed
