What is Erythema Ab Igne (EAI) (Toasted Skin Syndrome)?
Erythema ab igne (EAI) refers to a skin rash caused by long-term exposure to heat that is lower than the level causing burns. It is known that this condition could lead to cancerous changes in the skin, especially in situations like prolonged exposure to heat from coal fires. In the past, it was commonly found in people frequently exposed to heat from stoves or coal fires, but more recently, it is linked to regular use of electronics like laptops or space heaters, particularly in homes without central heating.
Instances of this condition have been reported due to exposure to a variety of electronics. However, the common factor is long-term contact with a heat source, including virtual headsets and space heaters, which has grown during the COVID-19 pandemic. Crucially, the heat exposure linked with this condition is less than the level causing thermal burns, usually when the temperature stays below 45C.
Patients will typically describe using some external heat source, which causes a distinctive network-like dilatation of blood vessels. Therefore, EAI typically appears as a local skin area with a net-like red patch, often with some uneven skin coloration and, less frequently, skin thickening. The diagnosis is primarily based on the appearance, but the exact spot of the rash can provide essential clues. For example, EAI often shows up on the lower back—usually from using a heating pad—suggesting potential underlying muscle or bone issues. The rash may also show up on the abdomen due to using a heating pack or laptop to soothe internal pain, such as that resulting from pancreatitis or vomiting.
Another usual sight for EAI is on the front of the legs due to the use of space heaters. However, other areas, like the front of the thighs, might be affected, especially in the cases of laptop use. While this rash is mostly harmless, its presence could hint at chronic inflammation or even systemic illness, and should provoke further investigation. A closer examination can also point to possible cancer-related changes in the skin, requiring a referral for a biopsy when needed. As for treatment, often observation is enough, though some research suggests more intensive treatment may be necessary if cancer-related changes are present.
What Causes Erythema Ab Igne (EAI) (Toasted Skin Syndrome)?
The rash is usually linked to some kind of external heat source, making it a long-lasting skin condition caused by the environment. In the past, this rash was often associated with heat sources like open fires, wood-burning stoves, and kerosene lamps. Lately, however, common sources have shifted to include modern electronics like laptops. Essentially, any constant exposure to heat that’s not hot enough to cause burns can lead to this condition.
Erythema ab igne, the formal name for this rash, is directly caused by exposure to heat. But the exact location of rashes can tell us a bit more about what might be causing it. For example, some people get this rash on their legs or lower back due to using space heaters or heating pads. But when the rash shows up in unexpected places, it could hint at deeper underlying issues. A rash on the face or ears might prompt questions about electronics use, a rash on the abdomen might suggest the patient uses heat to relieve abdominal pain, and a rash in other areas might lead to questions about why and how the patient is using heat.
Risk Factors and Frequency for Erythema Ab Igne (EAI) (Toasted Skin Syndrome)
Erythema ab igne, a skin condition, tends to affect more women than men. In the past, it was thought to affect women ten times more often due to frequent exposure to things like coal fires. However, recent data reveals that women are still twice as likely to have this condition, often appearing on the front of their legs.
This condition can appear at any age, with the average age being around 28.6 years. Most of the skin changes are localized, usually due to exposure to certain heat sources such as heaters, stoves, laptops, tandoor ovens, or hot water bags.
- Erythema ab igne is more common in women, with recent data showing women being twice as likely to have it.
- This condition usually appears on the front of the legs.
- It can affect people of any age, with the average age around 28.6 years.
- Most affected areas are often due to exposure to heaters, stoves, laptops, tandoor ovens, or hot water bags.
Interestingly, the age distribution might hint at the underlying cause of this condition. For example, in older adults, it might appear due to chronic back or abdominal pain, potentially indicating underlying systemic or internal issues, including serious conditions like cancer.
Signs and Symptoms of Erythema Ab Igne (EAI) (Toasted Skin Syndrome)
People usually aren’t aware they have this skin condition and often find out during a physical check-up. Even so, some people may experience burning, itching, or stinging sensations in the affected area. The skin issue tends to be prevalent among people with a chronic history of using heating sources like heating pads, which may cause discomfort or pain on the abdomen, lower back, or joints.
Doctors will typically ask about exposure to any heat source in the area of the rash when taking a patient’s medical history. In the early stages of the condition, the skin usually shows a large red patch that fades upon pressing. Over time, this redness turns into a distinct net-like pattern of darker skin that doesn’t fade when pressed. There might be thinning of the skin on these dark patches, and areas of thickened skin may also appear.
- Burning, itching, or stinging in the affected area
- History of using heating pads or other heat sources on the skin
- Large red patch that fades upon pressing
- Darker, net-like pattern on the skin over time
- Potential thinning of the skin and areas of thickened skin
Testing for Erythema Ab Igne (EAI) (Toasted Skin Syndrome)
“Erythema ab igne” is a condition that is typically diagnosed based on the patient’s symptoms and history. Characteristic indicators include hardened or blistered areas of skin, chronic ulcers, or the presence of certain skin cancers. These skin changes arise after exposure to long-term heat, usually applied to ease chronic pain. As such, understanding the source of the patient’s ongoing discomfort is also important as they may need further help with this.
In situations where the diagnosis isn’t clear, a skin biopsy might be worth considering. This is because “erythema ab igne” can conceal other types of skin cancers, or even signs of internal cancers, such as colon cancer. Usually, additional tests or image-based investigations aren’t needed, unless they can help uncover the root cause of the constant pain. For example, tests for pancreatitis, or imaging of the abdomen, might be called for if the pain’s origin is tied to these areas.
Treatment Options for Erythema Ab Igne (EAI) (Toasted Skin Syndrome)
The first step in treating this condition is to stop exposure to the heat source causing it. The resulting discoloration in the affected areas may fade over time, ranging from months to years. However, in some cases, the areas might remain permanently discolored or scarred. Treatments such as topical tretinoin or hydroquinone can help manage lasting discoloration. Scarring should be monitored and treated if it becomes prominent or disfiguring.
If there’s any suspicion of unusual changes in the outer layer of skin, regular skin check-ups are recommended. This is crucial because this condition could potentially lead to squamous cell carcinoma, a type of skin cancer. Indeed, this condition exhibits changes that mimic those observed in pre-cancerous states, such as actinic keratosis. Hence, a topical treatment known as 5-fluorouracil has been shown to treat these abnormal changes if they occur.
What else can Erythema Ab Igne (EAI) (Toasted Skin Syndrome) be?
When doctors examine a skin condition characterized by discoloration forming a net-like pattern, they should also think about Erythema ab igne as a possible diagnosis. There are many diagnoses for this specific type of rash, including:
- Livedo reticularis
- Livedoid vasculitis
- Poikiloderma atrophicans vascular
- Cutaneous T-cell lymphoma
- Dermatomyositis
- Cutis marmorata telangiectatica congenita
- Genodermatoses
- Angiosarcoma
- Vasculitis
- Bullous disease
A key factor that differentiates Erythema ab igne from other similar looking rashes is that it typically appears after prolonged exposure to heat. This is different from conditions like Livedo reticularis and Cutis marmorata, which usually show up when exposed to cold. Other rashes might appear without any connection to heat exposure at all. Another interesting sign is in patients suffering from pancreatitis: they might display Livedo reticularis on their abdomen, chest and thighs. This is likely due to damage to the small veins under the skin caused by trypsin, an enzyme involved in digestion. This occurrence is known as Walzel’s sign.
What to expect with Erythema Ab Igne (EAI) (Toasted Skin Syndrome)
The future looks promising for people with erythema ab igne if they can avoid the heat source that caused it. However, if they continue to expose their skin to this heat, there may be permanent changes in the skin color and a potentially increased risk of skin cancer. Numerous case reports have shown erythema ab igne can either develop into squamous cell carcinoma (a type of skin cancer) or hide the presence of existing skin cancer. Therefore, there is still a possibility that erythema ab igne may turn into skin cancer in the affected areas, which should be taken into account.
Possible Complications When Diagnosed with Erythema Ab Igne (EAI) (Toasted Skin Syndrome)
While it is not very common, there can be complications where changes to the cells could lead to skin cancer, as detailed in some medical studies. The transformation typically involves symptoms such as abnormal skin hardening or the development of sores, which are preliminary indications of cancer.
Preventing Erythema Ab Igne (EAI) (Toasted Skin Syndrome)
It’s crucial to educate patients about the role of heat in causing this disease. This will not only aid in their treatment but also help prevent the disease from coming back. For patients who got this disease due to their work environment, they require special instructions on how to avoid exposure in order to improve their health. If a patient is suffering from long-term pain, it might be beneficial to look into other methods for managing pain. This will prevent them from being exposed to the heat source repeatedly, which could worsen their condition.
