What are the other Names for this Condition? (Also known as/Synonyms)

• IGH (Idiopathic Guttate Hypomelanosis)
• Leukopathia Symmetrica Progressiva

What is Idiopathic Guttate Hypomelanosis? (Definition/Background Information)

• Idiopathic Guttate Hypomelanosis (IGH) is a benign and asymptomatic skin condition of unknown cause resulting in numerous light-colored irregular spots on the front part of the legs (below the knees) and on the lower arms. The condition is more often observed in Caucasians (fair-skinned individuals), but may occur in all racial groups
• Some medical researchers believe that Idiopathic Guttate Hypomelanosis occurs from long-term sun exposure combined with ageing factors. The condition generally presents cosmetic issues, and a treatment may be undertaken if warranted. The prognosis is typically good, even though the skin spots are known to be persistent

Who gets Idiopathic Guttate Hypomelanosis? (Age and Sex Distribution)

• Idiopathic Guttate Hypomelanosis may be seen in individuals of a wide age category, but most commonly they arise in young adults (around 30 years of age). The incidence is known to increase after 40
• Both males and females are affected; a greater number of cases are reported in young and middle-aged women
• Worldwide, there is no racial or ethnic preference observed
• However, the condition is predominantly noted in fair-skinned individuals (such as Caucasians). Dark-skinned individuals are also affected, and the pigment contrast is more pronounced in them

What are the Risk Factors for Idiopathic Guttate Hypomelanosis? (Predisposing Factors)

The risk factors for Idiopathic Guttate Hypomelanosis include:

• Caucasians
• Exposure to sun
• Advancing age - the condition is known to increase in incidence after middle-age
• A family history of the condition may be a risk factor, although the correlation is not well established

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases one’s chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Idiopathic Guttate Hypomelanosis? (Etiology)

The cause of Idiopathic Guttate Hypomelanosis is not well-understood (idiopathic). No infectious or genetic factors have been clearly identified. Trauma or injury is not known to be presently causative.

However, some researchers believe that it may be due to:

• Advancing age that causes a reduction in the melanocytes (cells that produce pigments)
• Chronic exposure to sun causing skin damage
• Some believe that the condition may be part of a non-sun damage skin condition such as seborrheic keratosis

What are the Signs and Symptoms of Idiopathic Guttate Hypomelanosis?

The signs and symptoms of Idiopathic Guttate Hypomelanosis may include:

• Presence of numerous asymptomatic light-colored spots (hypopigmented spots)
• These “drop-shaped” (guttate) skin spots are smooth; sometimes, they are slightly scaly
• The spots/macules are usually seen on the forearm or shin (below the knee)
• However, other sun-exposed areas, such as the face and neck, shoulders, and legs, may also present these spots
• The size of the spots vary from 2-5 mm; some are even 10 mm in size
• No pain or discomfort is noted

How is Idiopathic Guttate Hypomelanosis Diagnosed?

A diagnosis of Idiopathic Guttate Hypomelanosis may involve the following exams and procedures:

• Physical examination of the individual and medical history evaluation
• Dermoscopy: Dermoscopy is a diagnostic tool where a dermatologist examines the skin using a special magnified lens
• Wood’s lamp examination: In this procedure, the healthcare provider examines the skin using ultraviolet light. It is performed to examine the change in skin pigmentation
• Skin biopsy (if required): A skin tissue biopsy is performed and sent to a laboratory for a pathological examination. The pathologist examines the biopsy under a microscope. After putting together clinical findings, special studies on tissues (if needed) and with microscope findings, the pathologist arrives at a definitive diagnosis

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Idiopathic Guttate Hypomelanosis?

The possible complications due to Idiopathic Guttate Hypomelanosis include:

• Emotional stress due to cosmetic issues
• Persistence of the skin spots
• Treatment complications

How is Idiopathic Guttate Hypomelanosis Treated?

In many individuals, a treatment of Idiopathic Guttate Hypomelanosis may not be necessary since the condition is typically benign and asymptomatic. However, if there are any cosmetic concerns, then the healthcare provider may suggest the following treatment measures:

The treatment measures available for Idiopathic Guttate Hypomelanosis include:

• Spending less time in the sun
• Application of topical sun protection creams (oil-free sunscreens)
• Using wide-brimmed hats and covering oneself well before heading out into the sun
• Use of topical steroids and retinoids
• Cosmetic masking of the spots using suitable creams and lotions
• Cold therapy or cryotherapy

Regular follow up visits with the healthcare provider is recommended.

How can Idiopathic Guttate Hypomelanosis be Prevented?

Presently, it is not possible to prevent Idiopathic Guttate Hypomelanosis since the cause of the condition is unknown. However, the following factors may be considered to reduce one’s risk for the same:

• Limit exposure to direct sunlight
• If this is unavoidable (like due to an occupational requirement), then take safety steps to reduce exposure to the UV rays by using sunscreens with high sun-protection factor, wide-brimmed hats, and suitable protective clothing
• If sun exposure is unavoidable, keep oneself well hydrated

What is the Prognosis of Idiopathic Guttate Hypomelanosis? (Outcomes/Resolutions)

The prognosis of Idiopathic Guttate Hypomelanosis is generally good as the condition is benign and symptom-less.

• However, the characteristic skin spots may become a cosmetic issue for some individuals due to its persistence
• A treatment of the condition may make the visual appearance of these hypopigmented spots worse in some cases

Additional and Relevant Useful Information for Idiopathic Guttate Hypomelanosis:

The following DoveMed website link is a useful resource for additional information:

https://www.dovemed.com/healthy-living/skin-disorders/