Woman (47) died after suffering reaction to common drug for skin conditions, inquest hears

A 47-year-old woman suffered a fatal reaction to a common drug prescribed by specialists to treat severe skin conditions, an inquest has heard.

Tan Poh Kwai, a married mother of one from The Place, Dunboyne, Co Meath, died on May 30, 2020 in the intensive care unit at St Vincent’s University Hospital in Dublin.

Coroner, Clare Keane, returned a verdict of death by misadventure after finding that Ms Tan had died “on the balance of probabilities” from a reaction to a drug.

Dr Keane said she had been unable to substantiate references in evidence which suggested that the patient may also have been taking some Chinese medicines to treat her skin condition.

An inquest into Ms Tan’s death heard she developed DRESS syndrome – a condition caused by a severe reaction to a drug – after being prescribed Dapsone to treat a severe rash on her body.

Ms Tan’s daughter, Yen Ching Au, told the inquest that she did not think her mother had taken any other medication besides treatments which had been prescribed by her doctors.

The deceased, who came from Malaysia but was known as Joyce in Ireland, had first visited her own GP, Dolores Rafter, about an itchy rash on her body in December 2019 and January 2020.

Dr Rafter gave evidence of prescribing a number of medicines but said she had not considered Dapsone as she did not specialise in dermatology.

A sitting of Dublin District Coroner’s Court heard the patient visited another GP, Anas Mansour, at the D15 GP clinic in Blanchardstown in January 2020.

Dr Mansour, who has a qualification in dermatology, initially prescribed the patient with a number of topical treatments which caused the itchiness to subside but not the rash.

The GP said he thought Ms Tan might have coeliac disease as he felt she might have dermatitis herpetiformis, which is linked to sensitivity to gluten products.

Dr Mansour said Ms Tan was due to arrange to get a blood test at his clinic after being prescribed Dapsone for 30 days on February 12, 2020 as part of monitoring the patient because he was aware the drug could cause liver damage.

However, he said she cancelled the appointment.

Dr Mansour said that he was subsequently told by a hospital doctor, who informed him that medical staff were puzzled over how Ms Tan had suffered multiple organ failure, that she had also been using Chinese remedies.

However, he confirmed that Ms Tan had never said anything to him about taking such medication.

Under cross-examination by counsel for Ms Tan’s family, Ellen Gleeson BL, Dr Mansour said he advised her about the potential side-effects of Dapsone and that she should stop the medication if new rashes developed.

The doctor said he would have informed her about the “seriousness” of the medication, which the inquest heard is regularly prescribed for “off-licence” use in Ireland to treat skin conditions.

Dr Mansour stressed that there was nothing which prohibited him from prescribing the drug for Ms Tan.

The inquest heard the patient was admitted to Beaumont Hospital on April 4, 2020 with abdominal pain and peeling of her skin.

A consultant hepatologist, John Ryan, said the patient was discharged on April 16, 2020 after being diagnosed with drug hypersensitivity but was readmitted one week later with anaemia, nausea and vomiting.

Prof Ryan said Ms Tan was examined by a lot of specialists but her condition was “not exactly clear”.

Ms Tan was transferred to St Vincent’s University Hospital on May 16, 2020 for possible liver transplant due to the chronic liver disease.

In reply to questions from the coroner, Prof Ryan said it was impossible to say that Dapsone had definitively caused the patient’s condition but it was “very likely”.

He claimed the use of Chinese medicines would be a concern but he had received no definite confirmation that Ms Tan had been exposed to them.

However, he confirmed there was a reference to Chinese medicines in the patient’s medical notes.

A consultant dermatologist at Beaumont, Muireann Roche, said DRESS syndrome was a rare condition which affected between one in 1,000 and 10,000 patients and had a mortality rate of around 10pc.

Dr Roche accepted that Dapsone was the most likely cause of her condition but added there was no specific test to verify it.

The inquest heard that Dapsone was used widely in clinical practice to treat many severe, chronic inflammatory skin conditions.

The consultant said she did not believe there were any national guidelines about use of the drug.

Under cross-examination, Dr Roche said she believed some GPs might prescribe Dapsone but in her own experience it was “not common”.

However, she stressed that she was “very comfortable” about prescribing the drug.

A consultant hepatologist at St Vincent’s, Diarmaid Houlihan, recalled the patient has “a horrible skin condition with breaks in her skin all over her body”.

Prof Houlihan said the condition of the patient, who became unsuitable for a liver transplant, was consistent with DRESS syndrome.

In a closing submission, Ms Gleeson called for a verdict of death by misadventure as Dapsone was the most likely explanation for what happened.

Counsel for Dr Mansour, Paul Twomey BL, argued a narrative verdict would be the “safest” option.

Dr Keane made a finding that the cause of death, based on post-mortem results, was septic shock due to acute liver failure arising from a drug reaction.

The coroner said the patient had most likely suffered a reaction to Dapsone as the issue over whether she had taken any other non-regulated remedies had not been resolved.

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