Medical Case Study: Rapid Deterioration After a Mild COVID-19 Diagnosis

The following is an interactive article focusing on a medical case study. Use the information below to deduce what medical condition the patient was experiencing. There will be options at the end, each with a brief explanation of what each condition is to help you make your diagnosis. Please post your conclusion and why you chose it in the comments. After some time has passed, the correct answer will be revealed for you to check your work!

A 52-year-old woman was brought to the Emergency Department with impaired consciousness. Two days before her admission, she experienced thirst and fatigue, developed shortness of breath, and a fever of 38°C (100.4°F) the following day.

She visited a nearby hospital, where a COVID-19 antigen test came back positive. However, because her chest X-ray showed no evidence of pneumonia, she was sent home to isolate and manage what appeared to be a mild case of COVID-19. No bloodwork or urinalysis was done at that time. Shortly after returning home, she became confused and unresponsive, prompting emergency transport to a second hospital.

Here were the details gathered:

Patient History

Age: 52 years

Medical history: Schizophrenia (treated with monthly intramuscular aripiprazole)

Family history: No diabetes

Lifestyle: Non-smoker, no alcohol use

Vaccination status: Not vaccinated for COVID-19

Body mass index (BMI): 16.9 kg/m² (not obese)

She had undergone a routine physical exam two months prior, where her post-meal blood glucose was 100 mg/dL and HbA1c was 5.7%, indicating no prior diabetes.

Upon arrival at the Emergency Department, her vital signs were:

Blood pressure: 90/50 mmHg (low)

Pulse: 120 bpm (fast)

Temperature: 37.3°C (99.14°F)

Respiratory rate: 30 breaths per minute

Oxygen saturation: 100% (on 10 L oxygen)

Consciousness: Mildly impaired

Chest and abdominal exams were normal.

Laboratory Results:

Blood glucose: 1507 mg/dL (extremely high, normal range 2 hours after eating: less than 140 mg/dL)

HbA1c: 10.1% (6.5% or higher indicates diabetes)

Blood gas pH: 7.11 (acidic)

HCO₃⁻: 4.0 mmol/L (low)

Blood ketones: Strongly positive

Urine ketones: 2+ (normal is less than .6)

Creatinine: Elevated (renal failure)

C-peptide: 0.5 ng/mL (low)

Anti-GAD and anti-IA-2 antibodies: Positive

COVID-19 PCR: Positive

Chest CT: No pneumonia

These results confirmed a state of severe hyperglycemia, ketoacidosis, and low insulin production, pointing to a new-onset form of diabetes.

She was admitted to the ICU and started on continuous insulin infusion and aggressive IV fluid replacement. Within 10 hours, her blood glucose dropped to 247 mg/dL, and her blood pH normalized to 7.46. Her breathing and level of consciousness improved as well. She was transitioned to basal-bolus insulin therapy, with glargine once daily and lispro before meals. Over the course of ten days, her blood glucose levels stabilized between 112 and 142 mg/dL, and she was discharged home.

At her one-month follow-up, her HbA1c was 7.1%, and she had no lingering effects of COVID-19.

Summary

The patient’s COVID-19 infection was mild, yet she developed a life-threatening metabolic crisis shortly after infection.

Her autoimmune markers (anti-GAD and anti-IA-2 antibodies) and depleted C-peptide indicated that she had lost her ability to produce insulin.

COVID-19 may have triggered an autoimmune reaction against pancreatic beta cells, rapidly causing insulin deficiency and severe hyperglycemia.

Possible Diagnoses

1. Type 2 Diabetes Mellitus with Diabetic Ketoacidosis (DKA)

A chronic metabolic disorder where the body becomes resistant to insulin, causing elevated blood glucose. In severe stress (such as infection), it can trigger DKA. Typically occurs in overweight adults.

• Why it fits: The patient had high blood sugar and DKA.

• Why it doesn’t: She was not obese and had positive autoimmune markers, which are not typical for type 2 diabetes.

2. Hyperosmolar Hyperglycemic State (HHS)

A severe complication of diabetes involving extremely high blood sugar and dehydration, but usually without ketoacidosis, generally affecting those with Type 2 diabetes. Symptoms include excessive thirst and mental status changes, and it develops over days or weeks.

• Why it fits: Her glucose was very high, and she did present with thirst.

• Why it doesn’t: HHS usually develops over time, whereas her symptoms were sudden in onset. She had strong ketones and metabolic acidosis, making DKA more likely.

3. Antipsychotic-Induced Type 2 Diabetes

High blood glucose can be an unexpected side effect of some antipsychotics, sometimes leading to DKA. Unlike Type 2 diabetes, which develops via other methods, sometimes ceasing or changing the medication can reverse the condition.

• Why it fits: The patient was on the antipsychotic aripiprazole for schizophrenia.

• Why it doesn’t: Her autoimmune tests were positive, which is not characteristic of Type 2 diabetes.

4. Acute-Onset Type 1 Diabetes Mellitus (Autoimmune Diabetes)

An autoimmune condition in which the immune system destroys insulin-producing pancreatic beta cells, leading to DKA. While it is usually diagnosed in childhood, it can also develop after viral infections, such as COVID-19.

• Why it fits: Positive anti-GAD and anti-IA-2 antibodies, low C-peptide, recent viral infection, rapid onset of insulin deficiency, and presence of DKA.

• Why it doesn’t: The patient was 52 years old, which is older than the typical onset age for type 1 diabetes.

What is your diagnosis for the patient? Comment down below!

Thank you for reading,

Ashby Glover

Source:

Mariko Zenri, Mariko Higa, Kayoko Ikehara, Takamasa Ichijo, and Takahisa Hirose. “A Case of Acute-Onset Type 1 Diabetes Mellitus with Diabetic Ketoacidosis Triggered by COVID-19.” American Journal of Case Reports 24 (September 2023): e940986-1–e940986-5. doi: 10.12659/AJCR.940986