limited active range of shoulder motion; Injected limb mobility decreased; inadvertent intratendinous pertussis vaccination/over penetration of the vaccination needle through the deltoid to the depth of the greater tuberosity of the humerus; inadvertent intratendinous pertussis vaccination/over penetration of the vaccination needle through the deltoid to the depth of the greater tuberosity of the humerus; Arthus reaction; rotator cuff tear; Left shoulder pain/chronic left shoulder pain; This case was reported in a literature article and described the occurrence of arthus reaction in a 60-year-old female patient who received DTPa (Reduced antigen) (dTpa vaccine) for prophylaxis.   On an unknown date, the patient received dTpa vaccine. On an unknown date, several days after receiving dTpa vaccine, the patient experienced arthus reaction (serious criteria GSK medically significant), rotator cuff tear, shoulder pain, joint range of motion decreased, injected limb mobility decreased, inappropriate route of vaccination and wrong technique in drug usage process. The patient was treated with nsaid's (Nsaid), non-drug therapy (Ice Pack (No Medication)) and corticosteroid nos (Corticosteroid Injection (Generic Ingredients Unknown)). On an unknown date, the outcome of the arthus reaction, rotator cuff tear, shoulder pain, joint range of motion decreased and injected limb mobility decreased were recovered/resolved and the outcome of the inappropriate route of vaccination and wrong technique in drug usage process were unknown.   The reporter considered the arthus reaction, rotator cuff tear, shoulder pain, joint range of motion decreased and injected limb mobility decreased to be related to dTpa vaccine.  Additional details were reported as follows: This case was reported in a literature article and described the occurrence of vaccination induced partial thickness rotator cuff tear; arthus reaction and Inadvertent intratendinous pertussis vaccination in a 60-year-old female patient who was vaccinated with unspecified tetanus, diphtheria and acellular pertussis (TDaP) vaccine (manufacturer unknown) for prophylaxis.  The patient was thin with very small body habitus and small muscle mass, right-hand dominant female with no significant past medical history. The patient had no previous history of left shoulder pain or functional limitation. No information on patient's family history or concurrent condition or concomitant medication was provided. On an unspecified date, the patient received intramuscular diphtheria, tetanus and pertusis (TDaP) booster vaccination in her left posterior deltoid (batch number not provided) by her primary care physician. The age at vaccination was not provided.  On an unspecified date, several days following vaccination, the patient reported the atraumatic onset of significant left shoulder pain and inability to forward elevate her left upper extremity past 100 degrees or externally rotate past 30 degrees without pain. Despite use of nonsteroidal anti-inflammatory medication and ice, her symptoms did not improve. On an unspecified date, 6 weeks after vaccination, the patient resented to the office with a chief complaint of chronic left shoulder pain and limited active range of shoulder motion. On physical examination, the patient's left shoulder showed no evidence of atrophy or asymmetry compared to the contralateral side. The patient was nontender to palpation over her acromioclavicular or sternoclavicular joints. The patient was nontender over her bicipital groove and was primarily tender to palpation over the posterolateral aspect of her humeral head in the region of the greater tuberosity. The patient's active range of motion was forward flexion to 170 degrees, abduction to 170 degrees, external rotation to 50 degrees and internal rotation to the T8 level, with pain present on forward elevation and external rotation. The patient had rotator cuff strength graded as 5/5 on manual testing, but had reproduction of her pain symptoms with resisted infraspinatus testing. The patient had a moderately positive Hawkin's sign. The patient had an intact belly press and lift off exam indicative of intact subscapularis function. The patient was sensate to light touch in the left C5-T1 distribution and had 2+ radial pulses present. The patient had no cervical tenderness, had full, painless cervical range of motion (ROM) and a negative Spurlings test. Imaging, including 3 plain radiographic views of her left shoulder, was obtained and demonstrated no evidence of pathology. A magnetic resonance imaging (MRI) of the left shoulder was then obtained which demonstrated a broad based bursal surface medium grade partial thickness tear of the infraspinatus tendon extending inferiorly to involve the superior portion of her teres minor tendon attachment with a distinct area of intrasubstance fluid filled delamination present. The tear measured 0.6 cm × 0.8 cm in dimension, comprising 40% of the tendon substance. (T2 weighted left shoulder MRI coronal image, identified the needle track directed to the posterior aspect of the greater tuberosity). It was reported that the patient had arthus reaction and the reaction occurred within the substance of the rotator cuff tendons due to over penetration of the vaccination needle through the deltoid to the depth of the greater tuberosity of the humerus [An Arthus reaction is a painful, local reaction that was characterized by reaction of previously residing antibiodies (from a previous TDaP injection) to newly injected antigens]. With the diagnosis of a vaccination induced bursal-sided partial thickness rotator cuff tear caused by inadvertent intratendinous pertussis vaccination, the patient was started on a course of nonoperative management in the form of continued non-steroidal anti-inflammatory medication, a subacromial corticosteroid injection, and a physiotherapy regimen directed at rotator cuff stretching and strengthening. The patient's activity related left shoulder pain persisted for a three month period at which time it resolved. The patient was currently back to her usual activities without pain or functional limitation.  The authors considered the events of vaccination induced partial thickness rotator cuff tear; Arthus reaction to be associated with unspecified TDaP vaccine. (The author reported that linkage of the current patient's rotator cuff tear to the various inactive ingredients in the vaccine was less likely than a local reaction to the immunization. Glutaraldehyde (GA) is known to enhance collagen crosslinking; that might lead to increased tensile strength of the collagen fibrils. Formaldehyde had been shown to add to collagen's heat stability and ability to resist degradation by collagenase. Thus these substances would be more likely to enhance the tendon than to damage it. The proper technique for injection of the TDaP vaccine depends upon the patient's age and size. In a female adult less than 130 pounds, a 0.5 ml intramuscular injection into the deltoid was recommended. A 23-25 gauge needle 5/8ths to 1 inch in length should be placed at 90 degrees to the shoulder with care taken to ensure that the vaccination contents are deposited into the deltoid muscle belly. It was unclear from the patient history if these recommendations were followed. However, the patient had a very small body habitus and small muscle mass, it seemed very plausible that the vaccine was injected past the deltoid and into the substance of the rotator cuff tendons at their insertion onto the posterior aspect of the greater tuberosity of the humerus). The authors commented "One limitation of the current case report is the possibility that this patient developed rotator cuff dysfunction spontaneously due to a prior event and that the injection was not responsible for the partial thickness, bursal-sided rotator cuff tear that lead to her symptomatic presentation. It is also possible that an Arthus reaction occurred at the site of pre-existing rotator cuff damage leading to dysfunction. However, given that the symptoms occurred chronologically with the injection, we find these unlikely. Furthermore, there is MRI evidence of the needle track and fluid present at the site of tear corroborating our hypothesis that her injury was an unintended complication of the vaccination. In summary, we present the unusual complication of a vaccination-induced partial rotator cuff tear leading to a chronically painful shoulder. In very thin patients, administrators of vaccines should be very careful to stay intramuscular within the deltoid and avoid injecting the vaccine directly into the rotator cuff as this may lead to the consequences of an inflammatory reaction within the tendon leading to partial tearing".  This article is not available for regulatory submission due to copyright restriction.      Lab Comments: Lab test done on an unknown date. On physical examination, the patient's left shoulder showed no evidence of atrophy or asymmetry compared to the contralateral side. The patient was nontender to palpation over her acromioclavicular or sternoclavicular joints. The patient was nontender over her bicipital groove and was primarily tender to palpation over the posterolateral aspect of her humeral head in the region of the greater tuberosity. The patient's active range of motion was forward flexion to 170 degrees, abduction to 170 degrees, external rotation to 50 degrees and internal rotation to the T8 level, with pain present on forward elevation and external rotation. The patient had rotator cuff strength graded as 5/5 on manual testing, but had reproduction of her pain symptoms with resisted infraspinatus testing. The patient had a moderately positive Hawkin's sign. The patient had an intact belly press and lift off exam indicative of intact subscapularis function. The patient was sensate to light touch in the left C5-T1 distribution and had 2+ radial pulses present. The patient had no cervical tenderness, had full, painless cervical range of motion (ROM) and a negative Spurlings test. Imaging, including 3 plain radiographic views of her left shoulder, was obtained and demonstrated no evidence of pathology. A magnetic resonance imaging (MRI) of the left shoulder was then obtained which demonstrated a broad based bursal surface medium grade partial thickness tear of the infraspinatus tendon extending inferiorly to involve the superior portion of her teres minor tendon attachment with a distinct area of intrasubstance fluid filled delamination present. The tear measured 0.6 cm × 0.8 cm in dimension, comprising 40% of the tendon substance. (T2 weighted left shoulder MRI coronal image, identified the needle track directed to the posterior aspect of the greater tuberosity).