difficulty breathing; urticaria; Initial information received from a literature article on 16-Jul-2019.  This case is linked to cases 2019SA194917 and 2019SA194901.   The following is verbatim from the article:  Introduction: Diphtheria, tetanus, and pertussis vaccination is an integral component of the pediatric immunization schedule with DTaP administered to patients as a primary series at 2, 4 and 6 months of age and booster doses at 15 -18 months and 4-6 years of age. A single Tdap dose is recommended at 11 to 12 years old. Per the CDC, contraindications to DTaP and Tdap vaccination include anaphylaxis after a previous dose or to a vaccine component and encephalopathy within 7 days of administration.1 Anaphylactic reactions to vaccines are rare, occurring at a rate of approximately 1 per one million doses administered.2 At present, there is limited information regarding the outcome of diphtheria-tetanus vaccine in patients with a history of adverse events following prior immunization. We describe three patients who developed symptoms consistent with IgE-mediated reactions after DT or DTaP vaccination.  This case involves a 18 months old male patient who experienced difficulty breathing and urticaria, while he received vaccines HAEMOPHILUS TYPE B (HIB) VACCINE and DIPHTHERIA, TETANUS AND ACELLULAR PERTUSSIS VACCINE.  The patient's past vaccination(s) included three doses of DIPHTHERIA TETANUS ACELLULAR PERTUSSIS on an unknown date.  The patient's past medical history, medical treatment(s), family history and concomitant medications were not provided.   On an unknown date, the patient received a dose of suspect DIPHTHERIA, TETANUS AND ACELLULAR PERTUSSIS VACCINE produced by unknown manufacturer lot number not reported via unknown route in unknown administration site.  On an unknown date, the patient received a dose of suspect HAEMOPHILUS TYPE B (HIB) VACCINE produced by unknown manufacturer lot number not reported via unknown route in unknown administration site.  On an unknown date, the patient developed a serious difficulty breathing (dyspnoea) and urticaria following the administration of DIPHTHERIA, TETANUS AND ACELLULAR PERTUSSIS VACCINE and HAEMOPHILUS TYPE B (HIB) VACCINE. The patient was hospitalized for this event and discharged several hours after treatment.  It was reported that At age 14 years, patient presented for allergy evaluation. SPT results were as follows (wheal/flare): saline 3 mm/0 mm; histamine 7 mm/not recorded; 1:10 DTaP 3 mm/0 mm; full strength DTaP 0 mm/0 mm; 1:10 Tdap 3 mm/0 mm. IDT results were as follows: saline 0 mm/0 mm; 1:100 DTaP 5 mm/not recorded; 1:100, Tdap 0 mm/not recorded. He subsequently tolerated administration of full strength Tdap vaccine in three incremental doses over one hour in 20 minute intervals without adverse reaction.  Final diagnosis was urticaria and difficulty breathing.   The patient was treated with DIPHENHYDRAMINE (DIPHENHYDRAMINE), nebulized ALBUTEROL [SALBUTAMOL] (ALBUTEROL [SALBUTAMOL]) and oral corticosteroid as a corrective treatment.  The event outcome was reported as Recovering / Resolving (improved) on an unknown date for difficulty breathing and for urticaria.  Information on batch number was requested.  Documents held by the sender: none.; Sender's Comments: This literature case involves a 18-months-old male patient presented with Urticaria and difficulty in breathing after vaccination with DTaP and HIB produced by unknown manufacturer. Time to onset is compatible with the role of vaccine. Relevant lab data confirming that patient did allergy evaluation test at the age of 14 years in which patient tolerated administration of full strength Tdap vaccine in three incremental doses over one hour in 20 minute intervals without adverse reaction. Further information including patient's medical history, condition at the time of vaccination, concomitant medications, lab test excluding other etiology would be needed to fully assess this case. Based on available information and involvement of two vaccines, the role of vaccine cannot be individually assessed.