What is Bullosis Diabeticorum (Diabetes Blisters)?

Bullosis diabeticorum, also familiar as diabetic bullae or bullous eruption of diabetes mellitus, is a special kind of skin condition that only happens in people with diabetes. The condition was first noted by Kramer in 1930 and further discussed by Rocca and Pereyra in 1963. Cantwell & Martz recognized in 1967 that patients with diabetes often had repeating, spontaneous blisters on their limbs and coined the term “bullosis diabeticorum.”

It’s seen mostly in individuals who’ve had diabetes for a long time and also have a disorder called peripheral neuropathy, affecting nerves away from the spinal cord. These skin blisters don’t cause pain and take between 2 to 6 weeks to heal on their own, leaving no scars behind.

What Causes Bullosis Diabeticorum (Diabetes Blisters)?

The exact reason why bullosis diabeticorum happens isn’t fully understood. Most people with this condition also have kidney or nerve damage from diabetes. Some scientists think it might be due to changes in the connective tissue found at the bottom layer of the skin caused by tiny blood vessel disease, known as microangiopathy.

Biopsies of skin where the blisters are found have shown some signs of small vessel disease, leading to the suggestion that this could be linked to the cause of the blisters. Some evidence also suggests that imbalances in calcium and abnormal carbohydrate metabolism might contribute to the condition.

Every once in a while, the idea comes up that an immune response might be causing blood vessel damage, especially in cases where immune markers show up after certain test. However, whether blood sugar control affects the development of bullosis diabeticorum is still uncertain.

Risk Factors and Frequency for Bullosis Diabeticorum (Diabetes Blisters)

Bullosis diabeticorum is a rare condition that only has about 100 documented cases. Approximately 0.16% of people experience this condition each year. Some research suggests that this condition may affect about 0.5% of people with diabetes in the United States. The true number may be higher as not all cases are reported. It generally occurs in individuals aged 17 to 84, but there was a reported case involving a 3-year-old. Bullosis diabeticorum tends to be more common in adult men with long-term uncontrolled diabetes, with a man-to-woman ratio of 2:1. It should be noted that even those with recent diabetes diagnoses or uncomplicated diabetes, and sometimes those with prediabetes, may experience this condition.

Signs and Symptoms of Bullosis Diabeticorum (Diabetes Blisters)

Bullosis diabeticorum is a skin condition that often affects people with long-standing diabetes. It typically begins with the sudden formation of one or more blister-like lesions, also known as vesicles or bullae, that appear on normal, non-inflamed skin. These blisters generally develop on extremities like toes, feet, legs, hands, and forearms, and are often painless. Occasionally, patients might feel a mild burning sensation. The blisters may appear spontaneously, without any known injury leading to their development.

The size of these blisters can vary from a few millimeters to several centimeters. They often begin as tight blisters, but become softer and irregular in shape as they expand. They might look similar to burn injuries. The blisters are filled with a clear, sterile fluid, which can sometimes be tinged with blood. If a bacterial infection occurs, the blisters can fill with pus.

Bullosis diabeticorum affects individuals with both types of diabetes: those who rely on insulin (insulin-dependent) and those who do not (noninsulin-dependent). It can also coexist with other conditions related to diabetes, including nerve damage (polyneuropathy), eye damage (retinopathy), and kidney damage (nephropathy). In some instances, the appearance of these blisters could be the first sign of diabetes.

Doctors will examine the lesions to determine their exact location and characteristics while also considering other potential diagnoses. In certain cases, a small tissue sample (biopsy) might be needed to accurately diagnose the condition, and a culture test may help identify any secondary infections that need to be treated.

Testing for Bullosis Diabeticorum (Diabetes Blisters)

If a doctor suspects that a patient has bullosis diabeticorum, which is a skin condition associated with diabetes, they will need to check the patient’s blood sugar levels and overall metabolic health. If the patient hasn’t been diagnosed with diabetes before, they should be tested for it as soon as possible.

After confirming a diagnosis of bullosis diabeticorum, close monitoring is necessary to prevent and treat any secondary infections that may arise while the skin is healing.

Given the increased chances of small blood vessel disease in people with diabetes who also have bullosis diabeticorum, regular eye and nerve system checks are important. It’s also crucial to assess kidney health, particularly by testing for a protein called microalbumin in the urine, which can indicate early kidney disease.

Treatment Options for Bullosis Diabeticorum (Diabetes Blisters)

The best way to manage a condition called bullosis diabeticorum, or diabetic blisters, is still under debate. These blisters have a reputation for clearing up on their own, within 2 to 6 weeks, even without treatment. Many experts suggest leaving the blister and its skin alone because it naturally provides a safe and sterile protection for the wound below it.

Medications, especially antibiotics, are only advised if there’s an additional infection caused by staph bacteria. Some experts suggest using a small needle to drain the blister or to create a tiny opening in the blister, followed by applying antiseptic or antibiotic cream. This approach is meant to alleviate discomfort and prevent more infections.

In some situations, specifically when the soft tissues become infected, a surgery might be needed because of the high chances of bone infection. When a blister is present, it is advised to keep it immobilized to prevent any damage. If the skin around the blister begins to die, it may be necessary to remove the dead tissue and possibly apply a tissue graft.

Just like with diabetic ulcers, if a blister opens, it will need careful wound management. Some patients with recurring diabetic blisters have been successfully treated using therapy that transplants bone marrow cells from the patient’s body.

When diagnosing bullosis diabeticorum, a condition that causes blisters in diabetic patients, doctors should consider several other conditions that could be causing the symptoms. These include but are not limited to:

Porphyria cutanea tarda and pseudoporphyria: These conditions also cause blisters, typically on the hands rather than the feet and ankles, which is common in bullosis diabeticorum. The blisters are generally small. Pseudoporphyria is not rare in diabetic patients, especially if they have other complications such as chronic kidney failure or heart disease.
Bullous pemphigoid and epidermolysis bullosa acquisita: These conditions can be quite similar to bullosis diabeticorum in appearance and test results, but they can be differentiated through additional testing and examining the locations of blisters. For example, patients with epidermolysis bullosa acquisita often get blisters on areas of the skin exposed to friction.
Bullous cellulitis: This should be considered if the skin around the blisters is red, warm, and tender.

Diagnosis can involve looking at porphyrin levels in the blood, since normal levels are generally observed in bullosis diabeticorum, and higher level can indicate the presence of blister-causing conditions like porphyria cutanea tarda. However, patients with severe kidney disease may have slightly increased blood porphyrin levels, which could contribute to blister formation. Additional tests might be needed to rule out other related conditions.

What to expect with Bullosis Diabeticorum (Diabetes Blisters)

Bullosis diabeticorum, a skin condition related to diabetes, is often self-healing and typically clears up on its own within a few weeks. The sores generally heal leaving no trace of color changes or scarring. However, there have been reports of recurring episodes that lead to ulceration and scars. It’s also possible for the symptoms to come back over time.

Possible Complications When Diagnosed with Bullosis Diabeticorum (Diabetes Blisters)

Normally, the skin abnormalities in diabetic bullosis, or ‘diabetic blisters,’ heal on their own in 2 to 6 weeks. However, these blisters can often come back in the same place or in different areas of the body. Sometimes, these blisters can become infected, which means that the fluid inside the blister becomes cloudy. When this happens, a medical professional may need to run a culture test to confirm the infection and recommend treatment. In some cases, the area with the diabetic blisters may develop a bone infection known as ‘osteomyelitis’. There have also been cases where the infection got so severe that an amputation was necessary.

Diabetic blisters heal on their own in 2 to 6 weeks
Blisters may return in the same or different areas
A secondary infection may develop, making the blister fluid cloudy
A culture test may be required to confirm and treat any infections
In some cases, a bone infection (osteomyelitis) might develop in the area around the blisters
Severe infections might lead to amputations

Preventing Bullosis Diabeticorum (Diabetes Blisters)

People living with diabetes should attend classes or sessions that explain how to properly take care of their feet. A detailed check-up of the foot should include looking at the skin, checking for any deformities, testing nerve function, and examining blood circulation, which may involve checking the pulse in the legs and feet. If there are wounds but no signs of infection in soft tissue or bone, there’s no need for antibiotic medicine. If there are acute infections, a suitable option could be a specific antibiotic therapy that targets gram-positive cocci, a type of bacteria.