Santos, Natacha; Pereira, Ana Margarida; Plácido, José Luís; Castel-Branco, Maria da Graça. Hospital de São João, EPE, Porto, Portugal

Local and systemic reactions are a known complication of subcutaneous

specific immunotherapy (SCIT).

Our aim was to evaluate the frequency and severity of these reactions to

SCIT administration in our hospital.

Local reactions were classified as immediate (occurring within 30 minutes) or

late (debut >30 minutes after injection) and according to swelling size (<5

cm, 5-8 cm or > 8 cm).

Systemic reactions were classified according to EAACI, Immunotherapy Task

Force (JACI 2006:61:S82).

A total of 517 patients were treated with SCIT in our clinic during this 2 year

period: 59,6% female, with a median age of 21, ranging from 4 to 68 years

old. Most of our patients had allergic rhinitis (Graphic 1) and underwent

polymerized SCIT (96,3%) to mites (47,1%) or pollen (43.9%).

Local reactions occurred in a total of 205 (39,7%) patients :

8 patients presented systemic reactions:

Local swellings with <5 cm were common and are to be expected; they were well tolerated and do not require any specific therapy. Larger local reactions were rare.

Despite their rarity, severe systemic reactions can occur. Our division is equipped and prepared to deal with cases such as anaphylactic shock.

The Patient Immunotherapy Record Form is a useful tool for immunotherapy administration and adverse reactions surveillance.

Table 1. EAACI Grading of Severity for Systemic Reactions

I Mild - localized urticaria, rhinitis or mild asthma (PF* < 20% decrease)

II Moderate - slow onset (>15 min) of generalized urticaria and/or moderate asthma (PF < 40% decrease)

III Severe - rapid onset (<15 min) of generalized urticaria, angioedema or severe asthma (PF > 40% decrease)

IV Anaphylactic shock – immediate generalized urticaria, stridor (angioedema), asthma, hypotension

Graph 1: Prevalence of allergic diseases in patients undergoing SCIT

Asthma

Rhinitis Asthma + Rhinitis

Rhinoconjuntivits Asthma + Rhinoconjuntivitis

These reactions were more frequent in women (70,2%, p<0,001) and in

patients under depot immunotherapy (Graphic 4). There was no association of

local reactions with age, type of allergic disease or vaccine composition.

4 mild reactions

3 moderate reactions

1 anaphylactic shock

all during induction phase of SCIT

2 of them with depot immunotherapy

78,9%

39,1%

21,1%

60,9%

Depot

Polimerized

With local reactions Without local reactions

(498 patients)

(19 patients)

p<0,001*

27 year old female with allergic rhinitis in the maintenance phase of SCIT to house dust mites.

Prompt care was provided

Of the patients enrolled to SCIT in this period, 39 abandoned therapy, of

which 3 had presented with systemic reactions.

Graphic 4: Proportion of patients under polimerized and depot immunotherapy with local reactions. * using Chi-Square Test

1,9%

26,7%

30,2%

12,8%

28,2%

Graphic 2: Number of patients with local reactions according to time of onset and severity

98,6% with

papules < 5 cm

79

Immediate

62

Late

64

Both 81,7% with

papules < 5 cm

*PF: Peak Flow decrease from baseline

Introduction

We performed a retrospective study with data collected from a Patient

Immunotherapy Record Form involving all patients who began treatment

with SCIT to aeroallergens in our division from January 2008 to December

2009.

Methods

Results

30,7%

28,7% 40,6%

Induction Maintenance

Graphic 3: Patients with local reactions according to immunotherapy phase

Induction + Maintenance