2017 HCHB_digital

Allergies
An allergy occurs when the body’s immune system overreacts to a normally
harmless substance (called an allergen). Symptoms vary and range from very mild
to potentially life-threatening. Allergies are a contributing factor to conditions such as
hay fever, eczema and asthma.
Allergens may be in the air or on things that are touched or eaten, and
encompass many different things. Environmental allergens can be grouped into
those that are seasonal (for example, pollens and moulds) and those that last
year round (such as house dust mites and pets). Other common allergens in New
Zealand include:
• foods such as cow’s milk, eggs, fish, peanuts and other nuts, soy, and wheat
(account for over 90% of all food allergies)
• insect stings or bites (see also Bites and Stings)
• latex
• medicines (for example, aspirin, penicillin).
While allergies are not directly inherited, people do inherit the tendency to be
allergic. A person prone to allergies is called atopic, and these individuals have
a tendency to develop new allergies, often to things that they have not been
allergic to in the past.
When a person who is allergic to a particular allergen is exposed to that
allergen, their body responds by overproducing immunoglobulin E (IgE)
antibodies. The antibodies attach themselves to immune system cells, called
mast cells, and trigger the release of histamine and other chemicals. Mast cells
are most commonly found in the skin, mucosa of the lungs and digestive tract,
as well as in the mouth, conjunctiva of the eye, and nose, and the release of
histamine causes allergic symptoms such as itching, redness, sneezing, swelling,
and tightness.
Initial assessment
A person’s symptoms depend on how the allergen entered the body, for example,
mosquito bites on the skin cause a characteristic wheal and flare reaction,
whereas allergic rhinitis caused by inhalation of pollens into the nose results in
sneezing, a blocked and runny nose, tickly throat and itchy eyes (see also Hay
Fever). Other symptoms include a swelling of the lips, face and eyes, hives or
welts on the skin (see also Urticaria), a tingling mouth, and with food allergy,
abdominal pain and vomiting. Symptoms may rapidly progress in some people
to anaphylaxis.
Symptoms caused by conditions such as hay fever or insect bites are usually
obvious; however, some allergic reactions are not so obvious, so ensure you ask
your customer for a full description of their symptoms and if they have any idea of
the likely cause. Refer customers with severe or recurring allergies to the pharmacist.
Emergency treatment should be sought for any customer who presents with facial
swelling or with breathing difficulties. Many people just buy treatments in case of
future exposure, so make sure that the product sold will be effective against their
typical symptoms. Always take a person’s history of allergy seriously, and ensure
they know what to do if they ever have a serious allergic reaction.
Diagnosing allergies
Although some people are aware of what is causing their allergy, many people
are not, and actually pinpointing the allergen can be a complicated process. A
medical and family history may be required, in addition to a physical exam, skin
prick testing, and/or blood tests.
Food diaries are often used to narrow down likely allergens in people with
suspected food allergies or intolerances. A food diary is a written record of a
person’s diet and any resultant symptoms over a set period of time. Over a period
of a week or two, a pattern may emerge. It is important to note, if reactions to
TREATMENT OPTIONS
Category Examples Comments
Adrenaline
Oral antihistamines
[PHARMACIST ONLY]
eg, adrenaline auto-injector device (EpiPen
Adult, EpiPen Junior)
[PHARMACY ONLY MEDICINE]
Non-sedating, eg, cetirizine (Razene,
Zetop), desloratadine (Aerius),
fexofenadine (Fexofast, Telfast, Xergic),
levocetirizine (Levrix), loratadine
(Claratyne, Loraclear)
Sedating, eg, promethazine (Phenergan*)
Customers with allergies should be trained on how to use an auto-injector device. EpiPen training pens are
available free on joining EpiClub (www.epiclub.co.nz). Inject into the upper thigh not the buttock. Always
call an ambulance following administration for further follow-up. ACC may reimburse cost of EpiPen used as
treatment for an anaphylactic reaction. Note: At the time of going to print, EpiPen was the only auto-device
available to purchase in New Zealand
Oral antihistamines help control total body itch and inflammation. Generally, non-sedating medicines do not
cause drowsiness; however, some people may be more sensitive than others. Customers need to be warned
about the risks of driving or operating machinery if they do get drowsy (see also Hay Fever).
Oral and topical (nasal and ocular) antihistamines, nasal corticosteroids and decongestants See Hay Fever for a list of products in this category
Emollients and topical corticosteroids See Dermatitis/Eczema for a list of products in this category
Products with an asterisk have a detailed listing in the Allergies section of OTC Products, on page 220.
Dual Action Relief
Non-drowsy
Antihistamine
for hayfever
+
Decongestant
for blocked
or runny nose
Maxiclear Hayfever & Sinus Relief combines a non-sedating antihistamine (Loratadine) with
a nasal decongestant (Phenylephrine) to simultaneously treat hayfever and a blocked or runny nose.
Page 14 HEALTHCARE HANDBOOK 2017-2018 Common Disorders