In their timely 2020 editorial,1 Vally and Grills explored how to save Christmas in the era of SARS-CoV-2/COVID-19 and how the activities of Santa Claus can take place under the circumstances of a pandemic. “[I]s the risk too great?” they asked. After offering their epidemiological and public health expertise, they concluded how modifying some work practices could protect both Santa and those he visits to allow COVID-safe Christmas days.

Also last Christmas, Ferner et al. reported on “Harms and the Xmas factor”.2 In closing, they asked “is it worth it?” and compared Christmas costs (harms) and benefits. Case reports and data about Christmas hazards were presented. For example, they referred to cases that may instigate a smile although the background might be a serious disease like “The propagation of syphilis by toys”.2 A 2009 article by Grills and Halyday3 dealt with the question of Santa Claus’ dubious public health credentials. When the authors challenged Santa as a healthy role model, they used circumstantial information and pointed to his smoking and overeating. Moreover, Santa's potential role as an infectious disease vector who may become “a contact tracer's nightmare”3 was emphasised. This should now be updated with regard to COVID-19.1

Our aim was to systematically collect scientific evidence of adverse health effects associated with Christmas in terms of hazards to which we refer as “Chrishaps” (we expressly mean not only injuries from accidents or falls, but also threats to health from other risks such as high-fat foods or allergenic substances). To this end, we conducted a systematic literature review regarding the conceivable novel festive hazards posed by COVID-19 and regarding injuries, mishaps, and accidents around traditional hazard sources. To this, we added results from an unsystematic Google search about Chrishaps.

Methods

Our May 7 literature search was conducted in the PubMed, Web of Science and Open Grey databases. We included all studies or reports in English, which focused on Chrishaps, particularly associated with decoration, gifts, menus, and Santa himself, and with the new challenge COVID-19. We excluded studies or cases not clearly related to Christmas or dealing with human tragedy due to psychiatric disorders, self-harming behaviour, violence, or car accidents4 around Christmas. Likewise, articles containing recommendations or indications of hazards without individual or aggregated injury-data or designating the sources were not considered. For detailed information on the search string, inclusion criteria and exclusion criteria, as well as the number of results (PRISMA Flow Diagram) see Box 1. Our systematic literature search was complemented by an unsystematic Google search for keywords like “Christmas” in connection with “injuries” or “accidents”.

Results

After applying the exclusion criteria, 30 articles remained from the systematic literature search,1, 2, 5-32 most of them case reports or retrospective analyses. For detailed information about publication type, occasion, and the Chrishaps from the included papers see Table 1.

Table 1. Results from the systematic literature search: Publication type, occasion, and Chrishap.

Reference year

Publication type

Occasion

Chrishap

Anonymous 19465

Essay

Eating Christmas pudding

‘calorie-overload’

Wyse 19706

Experimental study and retrospective analysis

Allergies from Christmas trees

26 (1.66%) in retrospectively analysed cases

94 (5.6%) identified via prospective analysis

Kiff 19837

Case report

Eating Christmas cake

Peritonitis in a 86-year-old woman after having Christmas cake with a plastic robin eaten along

Alderman 19858

Report/ Retrospective analysis

Exposures at Christmas fayre

Changes in voice pitch, inhalation of foreign bodies, and alcohol problems

Lewis 19879

Case report

Slipping on icy ground on Christmas eve 1883

General Ulysses S. Grant's probable hip fracture in 1883 was mis-diagnosed as muscle rupture

Massmanian 199810

Case report

Trimming a Poinsettia plant two days before Christmas

Phototoxic reaction with erythematous, papulovesicular, hyperpigmented lesions on a 56-year-old woman's face

Godwin 199911

Case report

Posting Christmas cards in letter boxes

Amputation of a 59-year-old woman's finger tip

Barron 200112

Case report

Exposure to blue-coloured bed linen as Christmas gift

‘Cyanosis’ suspected in a 18-year-old woman which was due to blue skin discoloration by the textile

Ibanez 200413

Case report

Exposure to Poinsettia plant

IgE-mediated rhinitis and asthma in a 6-year-old boy with latex allergy

Philip 200414

Case report

Inhaling a small plastic Christmas tree

Acute airway obstruction in a 2-year-old boy caused by the laryngeal foreign body

Bala 200615

Case report

Exposure to Poinsettia plant as a gift during a hospital stay

Symptoms of a latex allergy (macular rash) in a woman with a latex allergy due to the plant

Hasnip 200716

Experimental study

Measurements in Christmas pudding

Christmas pudding contained 20 µg/kg ethyl carbamate

Kimia 200917

Retrospective analysis

‘Holiday-related injuries’ related to Christmas ornaments

Ingestions were the mainly found injuries, followed by lacerations and eye injuries

Petersen 201118

Retrospective analysis

Plant exposures leading to calls to poison centre

An average of 3.4% of human exposures involved plants: Poinsettia at rank 3, holly at rank 4

Gordon 201319

Literature review

Falls/injuries related to Christmas activities

Mostly vertebra fractures, followed by fractures of the lower limb

Jacob 201420

Case report

Laptop as a Christmas present

Dermatitis in an 11-year-old boy caused by nickel sulfate allergy

Brieger 201421

Systematic review and experimental study

Alcohol consumption by medical personnel during Christmas lunch

Consumption of Christmas pudding marginally affected blood alcohol levels

Donath 201522

Experimental study

Physical demands on Santa Claus

Spatio-temporal gait, balance, and ground reaction reduced when wearing a Santa Claus costume

Wedi 201623

Report/literature review

Allergy triggers around Christmas

All types of allergies due to Christmas trees, Poinsettia, Christmas decoration, candles, and food

Driedger 201624

Retrospective analysis

Falls and severe trauma associated with putting up Christmas lights

Neurologic (e.g. subdural hematoma) and thoracic traumas (e.g. rib fractures) were most frequent

Carsin 201725

Case report

Aspiration of a LED-bulb as Christmas decoration

Aspiration in a 14-month-old girl

Verma 201726

Case report

Swallowing peppermint Christmas candies in whole

Epigastric abdominal pain in a 86-year-old edentulous man

Cairns 201827

Retrospective analysis

Exposures to glow sticks

Ingestions followed by ocular exposures

Heyworth 201928

Case report

Swallowing a Christmas confetti star

Retropharyngeal abscess in a 9-month-old girl

Vedel-Krogh 201929

Cohort study

Exposure to Christmas holidays

Positive association between Christmas holidays and total cholesterol/LDL values

Lauche 201930

Retrospective analysis

Injuries to Santa Claus himself or his helpers or his impersonators

6,351 injuries related to sleds and toboggans, 213 related to chimneys, but the injured party could not be clearly identified

Ferner 20202

Literature review

Christmas harms

Examples included falls, poisoning, inhalations, ingestions, and dermatitis

Vally 20201

Editorial

Hazards for/by Santa Claus in COVID-19

Santa has different risk factors for COVID-19, but it is unlikely that he would spread the virus

Wormser 202031

Letter to the Editor

Questioning whether Santa Claus should work in COVID-19-times

Santa Claus is not expected to be at risk for either acquiring or transmitting COVID-19

Griffin 202132

BMJ News

Christmas festive period

Rise of COVID-19 registered deaths

From these 30 articles, seven6, 10, 13, 15, 18, 20, 23 related to allergic/irritating or phototoxic reaction, six14, 17, 25-28 to inhaling, ingestion, or swallowing objects, another six5, 7, 8, 16, 21, 29 to (over)eating and drinking, five9, 11, 19, 24, 30 to falls/injuries, and three1, 31, 32 to COVID-19. Three articles2, 12, 22 could not be adequately sorted into any of the above groups. In addition, six articles were identified via the Google search.33-38 Box 1: Search string, inclusion / exclusion criteria, flowchart. Discussion

Last Christmas, Vally and Grills1 offered a timely exploration of whether Santa could represent a novel hazard when he became infected with SARS-CoV-2 and becoming a vector of the virus and COVID-19. If so, not only Santa but also the families he visits could be at risk from SARS-CoV-2.1, 31 Yet, the authors concluded that – with appropriate counter-measures – there should be minimal risk posed by Santa, and a COVID-safe plan was suggested. However, in some nations, such as Scotland and England, where travel and mixing restrictions were lifted for Christmas day,32 it appears plausible that infection rates rose as a result – even if this is difficult to attribute as causal due to the festive period coinciding with the rise of a new strain of the virus.32 Thankfully, safe and effective vaccines shall enable safer festive days for this Christmas.

But beyond the possible impact of the novel hazard SARS-CoV-2/COVID-19, what Chrishaps might we expect?

Our literature searches revealed various hazards. Allergic reactions were demonstrated to Poinsettia or Euphorbia pulcherrima Willd (a popular Christmas plant), Christmas trees, candles, or even gifts like a donated laptop.2, 6, 13, 15, 20, 23 Moreover, poisoning from plants like Poinsettia or holly is known and contact can lead to contact dermatitis.10, 18 Also described were intoxication (e.g. by glow sticks), aspiration or swallowing of Christmas decoration (including a Christmas tree-bulb or other glass ornaments, confetti stars, button batteries, a plastic robin or a plastic Christmas tree) or Christmas candies.2, 7, 14, 17, 25-28, 36 Even more astonishing was a case report of supposed cyanosis induced by the staining of a blue bed linen as a Christmas gift.12

Another qualifier for a Christmas gift, viz Christmas mail, has proven hazardous even before the festive days when a finger tip was lost in a mailbox together with the dropped off Christmas letters.11

No reports could be found that either Santa Claus himself or one of his companions were involved in accidents which should reassure insurance agencies.30 For the important question whether the risk of falling is greater with Santa's costume and Christmas sack than without, an empirical ‘yes’ was reported.22

But what about those who Santa visits? When decorating, there is a risk of falling, for example, when putting up residential Christmas lights24 or decorating the interior. Among these risks, falls from ladders or roofs were the most common, but also from furniture, with some significant injuries like lacerations, strains and sprains, or fractures.19, 24, 33, 35-38 Lifting heavy objects (e.g. a box of decorative materials) may cause injury to the lower back.38

Christmas dinners35 also posed risks. We cherish Christmas as a time for good food, drink and merriment. Yet, the (in)famous Christmas pudding (especially well known in Great Britain) must be appreciated as a potential health hazard due to the alcohol and ethyl carbamate it contains16, 21 (especially when doused in brandy and set alight). Overeating (‘calorie overload’), to our surprise, has been rarely identified5 as a Chrishap in our systematic literature search. However, a positive correlation between Christmas and higher cholesterol values was reported29 and, perhaps unsurprisingly, weight gain was associated with Christmas.34 Two other risks from eating were documented: abdominal pain after eating without chewing26 and eating a piece of Christmas cake together with a plastic robin.7 Other observed phenomena included higher-pitched voices in men8 and a decrease in female pregnancies reportedly due to hormones in battery turkeys.8

Importantly, with regards to Chrishaps it may not only be of interest what factually happens but also to whom and how long effects may last. In this vein, the 18th President of the United States, Ulysses S. Grant, experienced his Chrishap as a life-changing experience: slipping on black ice in a Christmas fall, he probably sustained a hip fracture but it was deemed as a muscle strain, which plagued him ever after, possibly due to Chrishaps-associated mis-diagnosis.9

Given the potential hazards and Chrishaps documented, implications for public health may need to be explored to reduce such risks. Systematic risk research is required given the majority of articles were case reports. To assess and discuss specific public health implications of Chrishaps higher level studies are needed along with targeted injury surveillance. Overall, further research and effective information may limit Chrishaps and ensure we have a safe and merry Christmas.