Category Archives: Immunology

Grape allergy

Commonly associated with apple, peach, cherry allergy (rosaceae).

You can be allergic to some grape varieties but ok with others. Some may be allergic to grape but not wine, whereas others might not tolerate grape, wine or raisins/sultanas/currants.

Apart from wine, there’s also white wine vinegar, and vine leaves (stuffed in Greek and middle eastern cuisine!

Some people complain of bloating with grapes, this is usually fructose intolerance rather than allergy.

Reactions to wine (symptoms such as flush, rhinitis, asthma, and migraine) are not rare, but can be caused by different things:

  • type 1 immediate allergy to grape
  • type 1 immediate allergy to moulds (“the noble rot” for example is a mould that gives Tokay and Sauternes their character)
  • intolerance reactions to histamine and sulphite.

LTP sensitization seen, associated with anaphylaxis.

Microbiome

Substantial evidence that alterations in the gut microbiome early in life “imprint” gut mucosal immunity, which is probably important for development of food allergy.

Maternal factors, timing and how solids introduced all likely to be important.

Experimental studies have shown that faecal transplants or other attempts to modify bacterial commenals can prevent or treat food allergy.

Mechanisms include restoration of gut immune regulatory checkpoints (eg retinoic orphan receptor gamma T+ regulatory T cells), the epithelial barrier, and healthy immunoglobulin A responses to gut commensals.

[Rima Rachid, JACI 2021]

Lanolin allergy

Prob less common than suspected or talked about in eczema circles. Allergy to medical grade lanolin particularly uncommon, cf raw wool.

Patch testing pretty non reproducible! Not all lanolin the same?! Presence of alcohol important?!

So some v vocal critics of allergy “panic”!

Lanolin in cosmetics tends not to cause any problems, presence of damaged skin may be important for reactions.

For moisturisers, the following are lanolin free:

  • Aveeno
  • QV
  • Hydromol ok too?
  • [Not E45]

For bath additives, the following are lanolin free:

  • Cetraben
  • Diprobath
  • Balneum
  • Doublebase
  • Hydromol
  • Dermol 600
  • [Not Oilatum]

Steroid creams seem to be ok, at least Eumovate, Betnovate, Fucibet.

Alpha-gal allergy

Described in 2015, revolutionary in that allergy is to an oligosaccharide (ie a sugar, not a protein), specifically galactose-alpha-1,3-galactose.

Accounts for anaphylaxis to cetuximab, a cancer drug, but even more bizarrely, allergy to red meat (beef and pork). The latter appears to follow sensitization through a tick bite, so is really only an issue in endemic areas eg parts of United States and Europe, Australia.

Anaphylaxis to red meat can be immediate or delayed, with or without exercise induction!

In a small series of beef allergic patients reported in 2003 (strong family history), skin prick and labial contact tests only positive in minority.  All positive on IgE.  In another series, most beef allergic were also gelatine allergic.  Interestingly, a proportion of “idiopathic” anaphylaxis turned out SPT positive for gelatine. 

Bovine specific albumin is another possible allergen for beef allergy.

In Asia allergy described to galacto-oligosaccharides in milk formula, also a carbohydrate!

Thought to be T cell indepedent!

IgE test available.

Maize allergy

Maize is also known as corn in English, but in America “corn” refers to wheat, so potential for confusion! Commonly used in Mexican cooking.

Allergy to maize is extremely rare. It is not one of the 14 allergens that has to be highlighted under UK/European law on ingredient labels. Cross reactivity with wheat, rice and other cereals seen on lab tests but rarely clinically relevant. It does seem to fit more with Southern European fruit allergy syndromes, including sunflower seeds.

Foods:

  • Sweetcorn, corn on the cob
  • Popcorn
  • Cornflakes and other breakfast cereals
  • Corn flour (used as a thickener so can be low level in lots of different things)
  • Baking powder often contains corn flour
  • Custard
  • Tortilla chips, tacos, nachos
  • Most wraps are made of wheat but some are made with maize or a mixture of the 2
  • Frazzles, Doritos, Squares, Hula hoops, Monster munch, Wotsits, Pom bears, Skips
  • Some of the toddler snacks by Organix/Ellas Kitchen etc
  • Cornmeal, used to make polenta and grits

Potentially corn flour could appear in tablets/medicines.

There are some reports of severe allergic reactions to fructose syrup derived from maize/corn, which is used in lots of things (including beer and other drinks). This probably isn’t a problem for most people with maize/corn allergy though, so you should only avoid this if anaphylaxis or likely previous reactions to it.

Corn oil certainly poses no allergy risk, as processing removes any allergenic proteins.

Latex allergy

The name for pure natural rubber. Found all over the place – foam (mattresses), condoms, balloons, seals, adhesives. In hospitals, BP cuffs, elastic bandages, catheters and ET tubes, pulse oximeters… Not so often in surgical gloves now. Can cause mild and severe (anaphylaxis) reactions, plus delayed (non type 1) allergy. Allergy first described in 1979, became epidemic in 1980s.

The rubber tree Hevea brasiliensis is not the same as “rubber plants” (Ficus) you get as pot plants, although you can be allergic to those too, of course.

About half of latex allergic patients also have fruit allergies, especially avocado, banana, kiwi, melon but also chestnut and tree nuts.

Certain high risk groups:

  • Spina bifida
  • Health care workers

Atopic or irritant dermatitis may also be caused by rubber chemicals rather then latex itself.

Diagnosis

  • Blood IgE test – as with other IgE tests, potential for false positives esp with grass/fruit allergy.
  • Skin prick test with standardised latex
  • Prick through suspected glove! Needs latex free environment, of course. Potential for reaction to powder, rather than latex…
  • Glove test – wet hand! Risk of anaphylaxis.

Risk of Anaphylaxis

As with other allergies, seems to vary between individuals. And previous reactions do not reliably predict future reactions.

With health care, difficult. First on surgical list. Label patient. Latex free environment, as far as possible. Reports of probable reactions from IV fluids and needle puncture of bungs in IV sets.

Need for careful occupational advice.

Allergy and mental health

Evidence that having a peanut allergy has worse quality of life for a family than having diabetes… Mostly due to fear of unexpected severe reaction, and restrictions on social activities particularly eating out, parties and holidays.

Allergic patients can feel embarrassed or even ridiculed for declaring their allergy. Allergy is often mocked in the media (Cobra Kai, the Box Trolls, Peter Rabbit).

School and nursery are a particular area of concern, whether the right foods will be served, whether teachers or other children might bring allergens into school (food is sometimes used in classes, for example making bird seed balls), whether reactions will be managed appropriately, school trips. Children have died in school (Nasar Ahmed, Mohammed Ismaeel Ashraf).

Mums tend to be more concerned by limitations in the child’s own social life, dads seem to care more about limitations in the whole family’s social life. [Stensgaard, Clin Exp Allergy 2017]. Mums are the ones most studied. There probably are significant differences between mums and dads. In some studies, parents overrate their child’s quality of life, but in others (particularly with teenagers) parents can be seen as over anxious. Teenagers tend to take on the perspective of the parent of the same sex.

How bad previous reactions have been, interestingly, does not in itself contribute significantly to quality of life – in some cases, not having ever had a reaction can make families more anxious, because they don’t know what to expect! In one study, having multiple allergies and having an adrenaline pen was associated with worse quality of life. [Protudger, Clin Transl Allergy 2016]

Parents can feel guilty if their child has a reaction, a failure of their duty to protect. Mums can feel guilty about having “caused” their child’s allergy, either through their own medical history or what they ate or didn’t eat in pregnancy (even there is no good evidence for this being a factor).

Better quality of life is seen in allergic families with greater self efficacy for food allergy management, and lower perceived likelihood of a severe reaction [Knibb, Pediatric Allergy & Immunology. 27(5):459-464, August 2016].

APPEAL-1 study

8 European countries, questionnaire study of adults and children with peanut allergy

Only a minority remembered getting any training in future emergencies or use of medication, after their initial reaction. There was a low rate of satisfaction with AAI training! 

43% reported bullying, and a third of these described it as severe. 

65% confident in ability to recognize a reaction, but only 45% confident about knowing when to use an AAI and 59% how.  62% say the carry AAI all the time.

25-30% said it was not easy (or rarely easy) to talk to friends or family about their allergy, although most felt confident talking to new people about their allergy. Friends and family were generally seen as “believing there is too much concern over allergy” even though overall they were seen as having a good awareness and understanding of allergy (cf other people, where this was seen as the opposite).

Dutch respondents had lowest rates of uncertainty and stress around activities, and for feeling anxious.  At same time, they had the highest rates of confidence around knowing when and how to use AAI.  France had highest rate of being made to feel different in a negative way, and feelings of isolation.

NB – likely to be the most affected families who participated.

[Dunngalvin, Allergy 2020]

Systemic onset JIA

Features

  • Prolonged pyrexia (see below)
  • Intermittent characteristic rash (see below)
  • Raised CRP, ESR, ferritin (esp over 1000 – also haemophagocytic syndromes, haemochromatosis, liver disorders, malignancy)
  • Poor response to IVIG (cf Kawasakis)
  • Leucocytosis (neutrophilia, can be leukaemoid)
  • Thrombocytosis
  • Arthritis
  • Hepatosplenomegaly
  • Generalised lymphadenopathy
  • Pericarditis

Can be systemically very unwell and potentially life threatening complications may occur early in the disease course (eg pericarditis, macrophage activation syndrome or HLH, sepsis). See the Big Sick film from Netflix. Start high dose corticosteroids after careful exclusion of other diagnoses, especially infection, Kawasaki disease, and malignancy – difficult when arthritis is absent! But maybe you have to look harder…

Systemic features may predate the arthritis by several weeks and occasionally longer. Typically involves small joints of the hands and wrists, ankles, hips, knees, and cervical spine – about 30% ultimately develop severe polyarthritis.

There are no pathognomic tests or agreed diagnostic criteria for SOJIA! Classic features:

  • quotidian (=daily) evening spiking temperature, that returns to or falls below baseline by the morning.
  • Rash is faint, salmon pink maculopapular, most obvious during pyrexia. Usually not on the face so easily missed – typically on the trunk, inner thigh and axillae, especially on areas of trauma or pressure (Koebner phenomenon).

Treat with IV methylprednisolone pulses (30mg/kg over 4 hours, max 1g, once daily for 3 days) and ibuprofen (seems better than piroxicam for SOJIA!). Oral prednisolone may then be used while methotrexate is introduced.