Mercaptopurine-induced Sweet's syndrome

Sweet's syndrome is an acute febrile neutrophilic dermatosis. Drug-induced Sweet's syndrome typically occurs soon after drug administration, with rapid resolution of symptoms with cessation of the offending agent. We report a man in his early 40s who presented with fever and widespread erythematous rash on a background of recently diagnosed mild stricturing ileal Crohn's disease. He was commenced on 6-mercaptopurine 12 days before presentation. Skin biopsy demonstrated diffuse infiltration of neutrophils in the upper dermis, dermal oedema, eosinophils and fibrin deposition. Symptoms rapidly improved with cessation of 6-mercaptopurine without requiring systemic corticosteroids.

Linezolid-induced lactic acidosis

Linezolid is a commonly prescribed antibiotic in clinical practice. Although thrombocytopenia and peripheral neuropathy are frequently encountered following prolonged administration of linezolid, lactic acidosis is a rare adverse drug reaction. We present the case of a patient on linezolid for disseminated multidrug-resistant tuberculosis who presented with vomiting, dyspnoea, hypotension and high anion gap metabolic acidosis. The initial presentation mimicked sepsis syndrome. Ketoacidosis and renal dysfunction were ruled out. There was no history of ingestion of toxins/toxic alcohols. Sepsis was unlikely because extensive radiological and microbiological testing could not identify an infection. Given the possibility of linezolid-induced lactic acidosis (LILA), linezolid was discontinued on admission. The patient's lactic acidosis resolved, and his overall condition improved. A retrospective diagnosis of LILA was thus established. LILA should be considered when patients on linezolid present with lactic acidosis and other causes for the lactic acidosis have been ruled out.

Black thyroid gland and tracheal cartilage

A woman in her 70s with a history of chronic minocycline use presented with complaints of a non-tender posterior neck mass. A thyroid gland ultrasound showed a highly suspicious right thyroid nodule. A total thyroidectomy revealed darkened discolouration of the thyroid gland and tracheal cartilage. The pathology report showed dark brown granules representing melanin. Chronic minocycline usage is known to cause pigmentation of nails, teeth, bones and the thyroid gland. Our case highlights the importance of recognising that long-term use of minocycline can cause discolouration of the thyroid and tracheal cartilage. Current case studies do not show any adverse health effects associated with black thyroid and tracheal cartilage. For patients who are to undergo neck surgery, physicians need to be aware of this side effect, and that further intervention, such as surgical resection, may not be required.

Case of acquired haemophilia a in Southeast Asia following COVID-19 vaccine

Acquired haemophilia A (AHA) is a rare bleeding disorder with high morbidity and mortality, but it is eminently treatable if diagnosis and treatment are prompt. We report a case of AHA in Southeast Asia following the administration of the Pfizer-BioNTech COVID-19 vaccine. A man in his 80s developed multiple bruises 2 weeks after his first dose of the COVID-19 vaccine. Diagnosis was delayed due to his cognitive impairment and low clinical suspicion. This led to a representation with worsening ecchymosis, a left thigh haematoma and symptomatic anaemia. Laboratory testing was notable for an isolated prolongation of the activated partial thromboplastin time, which remained uncorrected in the mixing test. Further testing confirmed the presence of factor VIII (FVIII) inhibitors and low FVIII titres of 6.7%. He responded to treatment with intravenous methylprednisolone and recombinant activated FVII. Screening for autoimmune diseases and malignancies was negative.

Late onset of pituitary apoplexy following gonadotropin-releasing hormone agonist for prostate cancer treatment

Pituitary apoplexy (PA) is a clinical condition characterised by a sudden increase in pituitary gland volume secondary to ischaemia and/or necrosis. Most cases occur in non-functioning pituitary adenoma but can also occur in functioning adenoma. Certain predisposing factors can result in PA and the use of gonadotropin-releasing hormone (GnRH) agonists for prostate cancer (PCa) is one such condition. Once diagnosed, both surgical and conservative management has been used for the treatment of PA. We present a case of a man in his late 50s who developed PA following treatment of PCa with leuprolide. His symptoms developed insidiously and he presented 6 months after symptom onset. Anterior pituitary hormone workup along with pituitary MRI confirmed the diagnosis of PA and patient was subsequently treated with adequate replacement of pituitary hormone with significant improvement in his symptoms. It is very important to keep a high index of suspicion for PA, especially among elderly patients receiving GnRH agonist treatment for PCa.

Elexacaftor, tezacaftor and ivacaftor: a case of severe rash and approach to desensitisation

We present a case of severe rash following induction of elexacaftor, tezacaftor and ivacaftor (ELX/TEZ/IVA) in a young adult male cystic fibrosis patient. While rash is a commonly reported side effect which resolves in 1-2 weeks with minimal intervention, our patient had presented with fever and widespread rash prompting medication cessation. After a washout period, reintroduction with 1/2 tablet of ELX/TEZ/IVA produced a similar systemic response within 24 hours. Repeat attempt, this time with 1/8 tablet and increasing in increments of an eighth daily, was successful and has allowed our patient to experience the transformative benefits of ELX/TEZ/IVA including improved pulmonary function and reduced episodes of infective exacerbation. This case illustrates one of the most common side effects of ELX/TEZ/IVA triple therapy, and our experience of desensitisation to ELX/TEZ/IVA in a challenging case of rash.

Multisystem organ failure secondary to acute generalised exanthematous pustulosis (AGEP) with atypical presentation resembling septic shock

A woman was admitted for sepsis secondary to cellulitis. After clinical improvement of sepsis, non-follicular small pustules were observed on the trunk, limbs and face while vesicles/bullae and skin exfoliation were noted on upper extremities. Larger systemic manifestations included fever, hypertension and tachycardia. Laboratory results revealed neutrophilic leukocytosis, eosinophilia, mild transaminitis and acute renal failure. Despite treatment for potential sepsis and discontinuation of offending agents, her condition worsened leading to haemodynamic instability and renal failure requiring vasopressor support, intubation and continuous veno-venous haemodialysis. Skin biopsy revealed a diagnosis of acute generalised exanthematous pustulosis (AGEP), a rare condition usually caused by antibiotic treatment. The suspected offending drug was clindamycin, with possible combined effects by metronidazole and/or vancomycin. Improvement of skin manifestations were seen within 48 hours of starting systemic steroids. Here, we present an uncharacteristic case of AGEP clinically presenting with atypical skin lesions, severe systemic involvement mimicking septic shock, which culminated in multisystem organ failure.

Drug-induced hypersensitivity syndrome with lupus manifestations due to mesalazine in a patient with ulcerative colitis

Mesalazine is often used as first-line therapy for ulcerative colitis. Several reports have pointed to systemic adverse reactions associated with this drug. Most have evoked a drug-induced hypersensitivity syndrome, while some have described lupus syndromes but with limited clinical and varied biological features. A 75-year-old man presented with fever, dyspnoea, chest pain, polyarthralgia, and myalgia, following mesalazine introduction. Clinical symptoms and low-titre positive antihistone antibodies disappeared after mesalazine withdrawal without recourse to steroids. Pericardial effusion and 8F-fluorodeoxyglucose uptake on positron emission tomography/CT scan, and glomerular haematuria and proteinuria also disappeared. Cytokine-lymphocyte transformation tests showed a strong sensitisation pattern with interleukin-5 production. This case advances our knowledge of the mechanism of mesalazine-induced adverse effects, namely via drug-induced hypersensitivity with lupus manifestations, which we are the first to report.

Sweet's syndrome in the setting of newly initiated risankizumab therapy for pre-existing psoriasis

Sweet's syndrome (acute febrile neutrophilic dermatosis) is a rare disorder of unclear aetiology characterised by painful cutaneous lesions, sometimes accompanied by systemic symptoms. It has been associated with several autoimmune conditions, drugs, malignancies and infections, though many cases are idiopathic. We describe a case of Sweet's syndrome in a 49-year-old man with pre-existing psoriasis following recent initiation of risankizumab therapy. There are very few reported cases of Sweet's syndrome in association with psoriasis and no existing reports in association with an IL-23 inhibiting medication. Further investigation of the potentially overlapping immunologic pathways implicated in cutaneous reactions to biologic agents and autoimmune conditions such as psoriasis may yield insights into the pathogenesis of such conditions and guide advancements in the rapidly evolving field of targeted biologic therapies.

Third cranial nerve palsy in an 88-year-old man after SARS-CoV-2 mRNA vaccination: change of injection site and type of vaccine resulted in an uneventful second dose with humoral immune response

Vaccines for SARS-CoV-2 currently authorised by the European Medicine Agency are effective, safe and well tolerated in practice. Awareness of rare potential vaccine-related adverse effects (AEs) is important to improve their recognition, management and reporting. An 88-year-old man attended the emergency department with incomplete palsy of the right third cranial nerve 3 days after the first administration of Moderna mRNA-1273 SARS-CoV-2 vaccine. Imaging ruled out a vascular accident and a vaccine AE was hypothesised. Two weeks of oral steroids led to the patient's recovery, but without evidence of humoral immune response to vaccine. Thus, full immunisation with a dose of Pfizer mRNA-BNT162b2 SARS-CoV-2 vaccine in a different site was attempted. This was uneventful and followed by a robust antibody response. Empirical change of site and vaccine brand may represent a tailored option to obtain full immune protection in selected patients, after vaccine AEs.

Acute respiratory distress syndrome precipitated by granulocyte colony-stimulating factor in undiagnosed Pneumocystis jirovecii pneumonia

We present the case of a 62-year-old man with rheumatoid arthritis who developed a leukaemoid reaction and acute respiratory distress syndrome (ARDS) following granulocyte colony-stimulating factor (G-CSF) administration that had been given to treat neutropenia secondary to methotrexate and leflunomide toxicity. Later it was established that he had Pneumocystis jirovecii pneumonia, which was treated to complete resolution with a course of corticosteroids and antibiotics. This case highlights the potential risk of G-CSF administration in an immune compromised individual in the midst of bone marrow recovery in the context of active infection. Recognition of immune escape syndromes is vital and requires an understanding of potential triggers and risk factors.

Serous macular detachments associated with topical travoprost

Here is presented a unique case of bilateral serous macular detachments as a side effect of topical travoprost (0.004%) therapy. Only three other cases in the literature have definitively associated this side effect with other topical prostaglandins. The aetiological and pathophysiological pathways remain to be clearly elucidated but are potentially related to increased choroidal vascular permeability. In this case, the subretinal fluid resolved rapidly and completely after cessation of travoprost drops, showing it to be a reversible pathology similar to prostaglandin-associated cystoid macular oedema. This uncommon association is therefore important to consider in the differential diagnosis of serous macular detachment. Increasing ophthalmic awareness could help to prevent unnecessary investigations in undifferentiated patients without other guiding historical or examination features. This may save time and expense for the patient and health systems.

Application of pharmacovigilance tools in a case of subacute anterior angle narrowing while under furosemide exposure

Sulfonamides have been related to drug-induced acute angle closure of the eye, but scarce reports exist concerning furosemide. We describe the second case of acute chamber narrowing (ACN) during furosemide exposure. A 65-year-old man with a renal transplant presented with ACN, after 3 months of furosemide intake. Finally, the patient required a bilateral iridotomy and right lens replacement. ACN has been associated with drugs containing sulfonamide derivatives, but an evaluation with pharmacovigilance scales for adverse drug reaction (ADR)-standardised causality assessment has not been provided. We use this case to illustrate how medicines and an ADR should be evaluated and reported. The spreading of pharmacovigilance information on what should be a rare and unexpected condition related to a drug could mean that other reports emerge about ADR with this drug and regulatory agencies perform consequently, as happened with topiramate.

Immune checkpoint inhibitor-induced diabetes mellitus with pembrolizumab

An 81-year-old woman with a background of metastatic melanoma on pembrolizumab with no history of diabetes was brought into the emergency department with polyuria, polydipsia and weight loss. The initial assessment was consistent with severe diabetic ketoacidosis (DKA) and prerenal acute kidney injury with no clinical evidence of infection. The patient was treated with fluid resuscitation and an insulin infusion and eventually transitioned to a basal-bolus insulin regime, which was continued after discharge. Diabetes autoantibody screen returned negative, and she was diagnosed with immune checkpoint inhibitor–induced diabetes mellitus (ICI-induced DM) due to pembrolizumab. The patient has clinically improved and pembrolizumab was continued. The aim of this report is to highlight the importance of recognising ICI-induced DM as a rare immune-related adverse event in patients receiving programmed cell death protein 1/programmed cell death protein-ligand 1 inhibitor therapy and provide clinicians with insight into immune checkpoint endocrinopathies with an emphasis on diabetes and DKA.

Adalimumab-induced sensory vasculitic neuropathy

Vasculitis and other autoimmune conditions are known complications of tumour necrosis factor alpha (TNF-α) inhibitor use. By definition, TNF-α inhibitor induced vasculitis is a secondary systemic vasculitis. However, its phenotype is varied and can present as an isolated vasculitic neuropathy. This presents a diagnostic challenge as the gold standard for diagnosis of a vasculitic neuropathy is a peripheral nerve biopsy that meets predefined histopathological criteria. Given the poor sensitivity of the peripheral nerve biopsy, it is important that clinicians take a good history and maintain a high index of suspicion, as this is a treatable iatrogenic condition. Here we present a case of adalimumab-induced sensory vasculitic neuropathy, treated according to the Peripheral Nerve Society guideline for non-systemic vasculitic neuropathy, given her disease phenotype.

Non-infective cystitis secondary to benralizumab immunotherapy

This case study discusses a patient who presented with severe lower urinary tract symptoms and pain after commencing immunotherapy for eosinophilic asthma. Initial aetiology was presumed to be infective but cultures were negative. Cross-sectional imaging showed extensive perivesical and periprostatic stranding and inflammation. He was initially treated with antibiotics and anti-inflammatories but a lack of clinical improvement led to a rigid cystoscopy which identified an inflamed, oedematous urothelium which was biopsied. Histology demonstrated extensive, full thickness superficial detrusor inflammation, with marked congestion, oedema and a mixed inflammatory infiltrate in keeping with a severe active chronic non-infectious cystitis, possibly secondary to benralizumab therapy. His benralizumab was stopped and his symptoms completely settled. We believe this is the first described case of severe non-infective cystitis which may be secondary to benralizumab. This case adds to the isolated reports of this rare side effect of some of the newer biological agents in use.

Granulocyte colony stimulating factor (G-CSF)-induced aortitis in a patient undergoing adjuvant chemotherapy for breast cancer

Granulocyte colony stimulating factor (G-CSF) is used to prevent febrile neutropenia post chemotherapy. Usually well tolerated with minimal side effects but aortitis is an extremely rare side effect previously reported. A 64-year-old woman treated with adjuvant chemotherapy including G-CSF for left breast cancer was admitted with fevers, neutropenia and markedly raised inflammatory markers after 7 days of her first cycle. Initially diagnosed with neutropenic sepsis, she did not respond to broad spectrum antibiotics with subsequent CT imaging revealing marked periaortic inflammatory changes consistent with aortitis and periaortitis. Extensive investigations for other causes of large vessel vasculitis were negative and G-CSF was the only causative factor. She rapidly responded to steroids with almost complete resolution of inflammatory changes on repeat imaging within 4 weeks and no recurrence on tapering of steroids. This diagnosis must be considered in patients presenting with fever and raised inflammatory markers post G-CSF treatment.

Disseminated cutaneous Mycobacterium haemophilum infection in a patient on infliximab for rheumatoid arthritis

Mycobacterium haemophilum is a rarely encountered pathogen that is difficult to identify given its unique growth requirements. It is most often seen in adult patients who are immunosuppressed due to advanced HIV or haematological malignancy. Our case highlights a typical presentation of an atypical pathogen in a patient with rheumatoid arthritis receiving anti-tumour necrosis factor therapy. This case represents an important patient population in whom this previously rare infection is increasingly common.

Proton pump inhibitors associated with rapid eye movement sleep behaviour disorder

We present the case of a 65-year-old woman diagnosed with rapid eye movement sleep behaviour disorder (REMBD) based on typical symptoms and confirmed with an inpatient polysomnogram. She was prescribed clonazepam and later temazepam but continued to have intrusive symptoms. She subsequently recalled that the onset of dream enactment coincided with starting high-dose omeprazole for acid reflux. With this insight, she stopped the omeprazole. Within days, the dream enactment and nocturnal movements subsided. She stopped taking the temazepam and was symptom free for a few months. However, she was started on lansoprazole for recurrent dyspepsia. Once again she experienced violent movements in sleep. This is the first time an association between proton pump inhibitors (PPIs) and REMBD has been reported. PPIs have many effects on the central nervous system and should be considered as a possible provoking factor in people presenting with REMBD.

Ceftazidime induced liver injury

A 65-year-old woman with type II diabetes mellitus complicated by non-healing ulcers with recurrent osteomyelitis was admitted for progression of cellulitis after treatment failure with an outpatient course of amoxicillin-clavulanate. She was found to have persistent osteomyelitis and started on ceftazidime for a culture documented Pseudomonas aeruginosa infection. After two parenteral doses, she had a rapid rise in liver function tests (LFTs) in a hepatocellular pattern. Due to rapid identification, all medications with potential hepatotoxicity, including ceftazidime, were discontinued and the LFTs promptly returned to baseline over 3 days. Of note, the patient did not experience any symptoms of liver injury. Other causes of acute liver injury were effectively ruled out, but the case was confounded by usage of other potential hepatotoxic medications. Still, the most likely culprit was ceftazidime, a rare cause of drug induced liver injury with very few reports in the literature.

Treatment-induced sarcoidosis in a patient with metastatic clear cell ovarian cancer

Sarcoidosis is a granulomatous disease that commonly presents with lung or lymphatic system manifestations. Diagnosis is often delayed due to variable clinical presentation. This is a case of a patient with metastatic clear cell ovarian cancer who developed disease reoccurence after definitive treatment with surgery and adjuvant chemotherapy. She was treated with multiple lines of therapy, including investigational agents. During this time, she developed mediastinal lymphadenopathy and hypercalcaemia. Due to suspicion that her presentation was not a manifestation of her malignancy, she underwent two lymph node biopsies revealing granulomatous disease. She was initiated on prednisone for management of sarcoidosis, which led to radiologic, laboratory and symptomatic improvement. Although the precipitating factor for this patient's sarcoidosis cannot be definitively determined, nivolumab is a possible culprit. This case highlights the importance of a broad differential diagnosis when a patient undergoing antineoplastic treatment develops mediastinal lymphadenopathy or hypercalcaemia.

Post-COVID-19 vaccination occurrence of splenic infarction due to arterial thrombosis

We present the case of an 82-year-old woman admitted to a regional emergency general surgery centre with severe left upper quadrant abdominal pain and tenderness within 21 days of receiving the first dose of the ChAdOx1 nCov-19 vaccine (Vaxzevria, AstraZeneca). Following further investigation through CT imaging, a thrombus was discovered in the patient's splenic artery resulting in a large splenic infarct. Splenic infarcts are rare and it is important to note the association between time of administration of the first dose of vaccine and the occurrence of thromboembolic complications in the noted absence of other risk factors for this condition. We hypothesise a link between Vaxzevria vaccine injection and a rare form of thromboembolic complication: thrombosis of the splenic artery.

Fatal case of delayed-onset haemolytic anaemia after oral artemether-lumefantrine

Artemisinin derivatives are used globally in the management of falciparum malaria. Postartemisinin delayed haemolysis (PADH) is a recognised adverse event contributing to severe anaemia. To the best of our knowledge, we report the first recorded fatal case of PADH. A 60-year-old woman presented with two episodes of collapse at home and feeling generally unwell. She had recently been treated for uncomplicated falciparum malaria 1 month prior with artemether 80 mg/lumefantrine 480 mg in Congo. Her results on admission revealed an anaemia (haemoglobin 43 g/L), raised lactate dehydrogenase and positive direct antiglobulin test that suggested an intravascular haemolytic process. She made a capacitous decision to refuse blood products in line with her personal beliefs. Despite best supportive treatment, she did not survive. This case highlights the importance of postartemisinin follow-up and should encourage discussion and careful consideration of its use in the context of lack of access to/patient refusal of blood products.

Is surgical exploration necessary in asymptomatic intestinal pneumatosis after lung transplantation?

Pneumatosis intestinalis is described as gas within the bowel wall and can be a sign of bowel ischaemia with a pending perforation. The described patient presented with the incidental diagnosis of pneumatosis intestinalis with free intraperitoneal gas on CT scan. His medical history included a successful lung transplantation. We here describe the clinical decision-making and evaluate our case with previous cases in the literature.

Nitrofurantoin-induced agranulocytosis

Idiosyncratic drug-induced agranulocytosis is a rare life-threatening adverse reaction characterised by an absolute neutrophil count <500 cells/μL of blood. Nitrofurantoin has been associated with haematological adverse events, but few agranulocytosis cases worldwide have been reported. We present a case of a 68-year-old woman who presented with fever and agranulocytosis following treatment with nitrofurantoin. Extensive workup for agranulocytosis, including a bone marrow aspirate, was unremarkable. Treatment with nitrofurantoin was discontinued, which led to a complete recovery of the complete blood count. This case stresses the importance of monitoring treatments, given that widely used drugs are not free from severe adverse reactions.

Life-threatening immune checkpoint inhibitor-induced myocarditis and myasthenia gravis overlap syndrome treated with abatacept: a case report

We present here the second documented case of severe immune checkpoint inhibitor-induced myocarditis successfully treated with abatacept. The patient was started on pembrolizumab for stage IIIA malignant melanoma, and after the first dose was admitted for worsening shortness of breath and weakness. Her symptoms were refractory to high-dose steroids and she decompensated rapidly necessitating cardiopulmonary resuscitation and subsequent intubation and mechanical ventilation. Intravenous immunoglobulin and plasmapheresis did not invoke significant improvement, so abatacept was then initiated. She began to show improvement and was eventually discharged to a skilled nursing facility. This case highlights a severe adverse reaction to an immunomodulator class steadily growing in its application. Providers of all specialties should be aware of the side effects and treatment options. Our case demonstrates that continued investigation into the utilisation of CTLA-4 agonists in the treatment of severe adverse reactions like myocarditis caused by pembrolizumab is required.

Sulfasalazine-induced drug reaction with eosinophilia and systemic symptoms (DRESS) with concomitant acute chikungunya virus infection: possible role of new viral trigger

Drug reaction with eosinophilia and systemic symptoms (DRESS) is designated as a potentially lethal adverse drug effect with characteristic signs and symptoms such as skin rash, fever, leucocytosis with eosinophilia or atypical lymphocytes, lymphadenopathy and liver or renal dysfunction. In addition to most commonly implicated drug category (aromatic anticonvulsants), lamotrigine, sulfonamides, dapsone and abacavir may also induce this syndrome. We describe here a case a sulfasalazine-induced DRESS with coexisting chikungunya fever. The shared presentation of fever with rash in both conditions made it a challenging diagnosis. Sulfasalazine hypersensitivity manifesting as DRESS has rarely been reported. Furthermore, we document chikungunya virus (CV) as a possible triggering agent for DRESS. To the best of our knowledge, CV as a viral aetiology in DRESS has not been reported previously in the literature.

Haloperidol-induced isolated lingual dystonia

A 28-year-old woman presenting with agitation and mania with psychotic features developed symptoms of isolated lingual dystonia shortly after the initiation of a haloperidol concentrate regimen.

Doxycycline-induced acquired haemophilia A

An 80-year-old man with no personal or family history of bleeding, presented to hospital with extensive haematomas and skin bruising after using doxycycline. His basic lab workup was concerning for a coagulopathy with an elevated activated partial thromboplastin time and significant anaemia. Mixing studies and other factor levels were tested that led to the diagnosis of acquired haemophilia A with low factor VIII levels and high factor VIII antibodies. He was started on steroids, but his haemoglobin level continued to drop. Later, during his treatment, he was given multiple therapeutic agents, including cyclophosphamide, rituximab and recombinant factor VII (NovoSeven-R). Gradually factor VIII levels increased and haemoglobin stabilised. The hospital course was complicated by COVID-19 pneumonia leading to acute respiratory distress syndrome; the patient eventually expired due to respiratory failure.

Immunotherapy-induced coeliac disease in curative lung cancer

The advent of immunotherapy has revolutionised the treatment of metastatic lung cancer and it has recently been established as the standard of care in the radical treatment of lung cancer. However, immune-related adverse events (IrAEs) frequently occur in patients treated with immunotherapy, and rare IrAEs continue to be identified. We report a case of immunotherapy-induced coeliac disease due to adjuvant durvalumab post-chemoradiotherapy in a patient receiving curative treatment for lung cancer. The patient had raised anti-tissue transglutaminase IgA and histological findings consistent with coeliac disease. This is the first published case report of probable immunotherapy-induced coeliac disease both with the immunotherapy drug durvalumab and in the curative lung cancer setting.

A probable case of collapse due to hyoscine patch

This case report highlights the potentially serious side effects of hyoscine and how a seemingly innocuous patch may confound patients and doctors alike. It demonstrates how easy it is to miss an obvious diagnosis when in fact a thorough medical history including an exhaustive drug history can easily point us in the direction of the diagnosis fairly quickly. Finally, hyoscine may cause potentially serious side effects and patients who are taking it, either orally or transdermally, should be made aware of these.

Methaemoglobinaemia in the perioperative period with regional block

Methaemoglobin is a form of haemoglobin with oxidised ferric (+3) iron rather than ferrous (+2) iron, which causes a leftward shift in the oxyhaemoglobin dissociation curve and prevents oxygen delivery. Anaesthesiologists need to be familiar with this differential diagnosis for hypoxia given the use of drugs in the perioperative setting known to induce methaemoglobinaemia, including benzocaine and lidocaine, antibiotics such as dapsone and anaesthetic gases, including nitric oxide. This case report details an interesting case of symptomatic methaemoglobinaemia in the perioperative period in the setting of dapsone use and an erector spinae block performed with ropivacaine.

Rare complication of ceftriaxone therapy: drug-induced thrombocytopenia (DITP)

A 62-year-old woman with a history of end-stage renal disease on haemodialysis, essential hypertension and type 2 diabetes mellitus was diagnosed with sepsis and placed on 600 mg oral linezolid every 12 hours and 1 g intravenous ceftriaxone every 24 hours. Blood cultures grew Streptococcus dysgalactiae, and she was switched to intravenous ceftriaxone 2 g daily. Platelet counts slowly trended down after starting ceftriaxone reaching 5 K/μL on day 12 of treatment. Ceftriaxone was discontinued and heparin-induced thrombocytopaenia was ruled out. She was switched to vancomycin and her platelet count improved. Given the temporal relationship between changing platelet counts and starting and discontinuing ceftriaxone, a diagnosis of drug-induced thrombocytopaenia was made.

Acute eosinophilic pneumonia: a fatal reaction to ado-trastuzumab

Ado-trastuzumab emtansine (T-DM1) is a monoclonal antibody drug conjugate approved for the treatment of HER2-positive breast cancers. Presented here is a case report of a patient who developed fatal pulmonary toxicity in the form of acute eosinophilic pneumonia while undergoing treatment with T-DM1. Prior to beginning T-DM1 therapy, this patient had been treated with two HER2-targeted agents (trastuzumab, pertuzumab) per National Comprehensive Cancer Network (NCCN) guidelines. This case represents a novel presentation of toxicity associated with T-DM1 while perhaps demonstrating additive toxicity associated with multiple lines of HER2 targeted therapies.

Ipilimumab and nivolumab induced immune-related adverse events in metastatic mucosal melanoma

Mucosal melanoma is a rare subtype of melanoma and represents a unique diagnosis and treatment challenge. Immune-checkpoint inhibitors (ICIs) have revolutionised metastatic melanoma treatment, and one of the leading regimens is the combination of ipilimumab (anti-cytotoxic T lymphocyte-associated antigen 4: CTLA4) and nivolumab (anti-programmed cell death protein 1: PD1). We report a case of a patient with metastatic mucosal melanoma treated with ipilimumab and nivolumab who developed multiple immune-related adverse events (irAEs) including uveitis, type I diabetes complicated by diabetic ketoacidosis, destructive thyroiditis, hepatitis and vitiligo. Endocrinopathies including type 1 diabetes and hypothyroidism were treated with insulin and levothyroxine. Hepatitis was responsive to steroids. She had sustained complete response 12 months after discontinuation of the combination therapy. With the wide usage of ICIs in multiple types of malignancies, it is important for general practioners to recognise common and serious irAEs due to ICIs.

Bullous fixed drug eruption following administration of the recombinant adjuvant Shingrix vaccine

A 51-year-old woman with Crohn’s disease presented with a bullous rash on her left arm and axilla 2 days after receiving her second dose of the recombinant adjuvant Shingrix vaccine. PCR for herpes simplex virus (HSV) 1, HSV 2 and varicella zoster virus was negative. Punch biopsy revealed changes that were consistent with a bullous fixed drug eruption. She was successfully treated oral prednisone and topical triamcinolone cream. This is the first known case of a bullous fixed drug eruption due to the recombinant adjuvant Shingrix vaccine.