IGH causes small pale-colored spots to develop on areas of the skin often exposed to the sun. These spots are benign, but treatments are available to address their appearance.

Idiopathic guttate hypomelanosis (IGH) is a skin condition that tends to affect older adults. As small pale spots appear on the skin, some people may become worried, but it’s a benign condition. Here’s what you need to know about this skin condition.

The classic symptom of IGH is a series of pale or white patches or lesions on areas of the skin that tend to be exposed to the sun. These often appear on the arms, legs (especially the shins), upper back, and face, although some suggest that IGH is less likely to show up on the face.

The spots can range in size from 1 to 10 millimeters (mm), but smaller ones tend to be more common. You can have one or two lesions or dozens of them.

In medical terms, “idiopathic” means there’s no identifiable cause, or the exact cause is unknown.

While experts aren’t sure of the exact cause of IGH, many believe a decrease in melanin from sun exposure seems to be responsible.

However, because of inconsistent findings in previous research, more research is needed to identify the cause.

Anyone can develop IGH, though increasing age is the most significant risk factor. While there are some reports in children and teens, IGH affects most adults over age 40.

Although IGH affects people regardless of sex or gender, women are more likely to get medical help. The American Osteopathic College of Dermatology also notes that women may develop the condition at a younger age than men, though rates eventually even out.

IGH may be more common in people who have light skin tones. However, the spots tend to be more noticeable on dark skin, and people of color are more likely to get medical help.

People with a family history of IGH also seem to be at increased risk for developing it themselves.

Is idiopathic guttate hypomelanosis rare?

IGH is a common condition but tends to become more prevalent as people age. Some research suggests that about 4 in 5 people over the age of 70 have some evidence of IGH.

IGH can look similar to some other skin conditions, such as vitiligo, an autoimmune condition in which patches of skin lose their pigment. However, unlike vitiligo, IGH lesions do not usually progress.

A doctor may want to examine your skin in the affected areas under regular and UV light. They may also use a technique called dermoscopy. This involves using a dermatoscope with a magnifying lens that allows the doctor to get a very close look at the skin, including skin structures that may be hard, if not impossible, to see with the naked eye.

In some cases, a doctor may perform a biopsy to rule out other conditions.

IGH is benign, so treatment isn’t necessary. However, some people are unhappy with their appearance and want to try to address the spots. So IGH treatment usually aims to improve the appearance of the skin with the lesions or spots.

Treatments you may try include:

Can you reverse idiopathic guttate hypomelanosis?

You can’t reverse IGH, but you may be able to treat it. Studies report variable degrees of success with various treatment approaches. However, evidence is very limited, and many attempts are not particularly effective.

The authors of a 2018 review of studies found that treatment only yielded about 50% improvement in the appearance of spots or lesions and that only 50% to 60% of people noticed any improvement.

IGH is benign, so it will not lead to cancer or other potentially harmful conditions. But it also will not go away on its own.

This can be disturbing to people who are concerned about the visible appearance of their skin and can cause some psychological trauma, as the authors of the previously mentioned 2018 review described outcomes. Anyone wanting to address their trauma might consider discussing treatment options with a healthcare professional.

You can’t change most of your risk factors (like increasing age or family history) for IGH.

However, because these spots are a sign of cumulative sun exposure, the key to prevention is sun protection.

Experts usually recommend sunscreen, sun-protective clothing, and other physical barriers to help prevent IGH from developing.

If you notice a cluster or spray of white or pale-colored spots that have sprung up on your forearms or your legs, you’re not alone. Many people develop these spots, especially as they age and accumulate more sun exposure.

These pale spots are often IGH. They’re not serious and are not a warning sign of cancer, so if you want to consider them as another sign of aging, you can.

However, if their appearance causes you distress, consider talking with a dermatologist. You can discuss the various treatment options to decide which one might be most appropriate for you to reduce the visibility of these spots.

A doctor may also want to discuss the importance of consistently applying sunscreen to areas of your skin that are exposed to the sun.