Although a skin rash can occur anywhere on the body, it often causes more stress when it appears on the face or other parts of the body that are commonly exposed. The concern may often be cosmetic but rashes are a sign of skin and sometimes systemic diseases. A rash on the forehead occurs for most of the same reasons as rashes elsewhere on the face and scalp. It may be an extension of rashes from the face or scalp or can be conditions that have a predilection for the forehead.
Skin Rash On Brow Or Forehead
Facial skin is usually thinner than most parts of the body and has a higher concentration of sebaceous glands (oil-producing glands). The skin on the forehead is largely the same as it elsewhere on the face. Therefore many of the skin conditions that affect the face may also involve the forehead. The additional factor is that the forehead, like the neck, lies next to the scalp and may therefore also develop many of the same afflictions that occur on the scalp.
A skin rash is any visible lesion on the skin. This simply means that the skin does not look or feel as it normally should. The skin may be red, whitish or silver, darker or even lighter than normal skin color, have pimples, be dry and crack or peel. Some rashes may also itch, pain or have a burning sensation while with other rashes there are no abnormal sensations. Depending on the condition and the severity, the sensory ability of the affected skin may also be altered, either being less sensitive or more sensitive than normal.
Causes of Forehead Skin Problems
There are a number of skin diseases that can affect the forehead. Most are not unique to the forehead, like cellulitis and impetigo (bacterial infections), measles (viral infections), insect stings/bites, dry skin (xerosis), shingles (herpetic neuralgia) and so on. Therefore forehead skin problems should be seen in the context of skin diseases elsewhere on the face or on the scalp. The conditions discussed below are commonly seen on the face and/or scalp, and the forehead is more likely to be affected with these skin diseases.
The pictures below are of the respective skin diseases but may not always reflect the presentation on the scalp. Most of the images have been sourced by Dermatology Atlas Brazil (atlasdermatologico.com.br).
Acne vulgaris is a common condition that affects the face. It is mainly seen in adolescents but can continue until adulthood. Sometimes acne only arises in adulthood. Acne is a result of sebaceous glands producing excess sebum (oil), the subsequent clogging of pores, inflammation and infection with skin bacteria. The main underlying cause is a hormonal fluctuation. The typical appearance is that of pimples (raised red lesions) but it may also appear as comedomes (blackheads or whiteheads), pustules and cysts. Forehead acne does not usually occur on its own but is more often an extension of face acne and/or scalp acne.
Fungal infections of the skin are common conditions. Due to the appearance of the rash, it is often referred to as ringworm but is not actually caused by a parasitic worm. Yeast infections of the skin are uncommon on exposed areas like the forehead. Instead it may be caused by skin fungi known as dermatophytes. Forehead ringworm (fungal skin infection) is often included under facial ringworm (tinea faciei) but sometimes the infection can start on the scalp and then extend to the forehead. A scalp ringworm (tinea capitis) is quite common.
One of the common causes of darkening skin rash is melasma. It is believed to be due to a combination of hormonal factors and sun exposure. However, the exact cause is not known. Typically the skin on the face is the most affected. The skin gradually darkens over times and it usually occurs as large patches on the face. This is a result of the pigment-producing cells in the skin (melanocytes) producing excess skin pigment (melanin).
Vitiligo is where there is loss of skin pigment causing the skin to become paler in color and eventually white. The hypopigmentation is usually limited to spots or patches which can coalesce into larger lesions. The exact cause of vitiligo is unknown. It is believed to be associated with genetic factors and possibly linked to repeated injury of the skin, autoimmune factors and oxidative stress. Sun exposure can cause the area to become red in color as the affected skin does not have the same protective ability without adequate melanin.
Eczema is a broad term to describe several different types of inflammatory skin conditions (dermatitis). The skin lesions may differ based on the type of dermatitis. Three of the more common types of dermatitis that are likely to affect the forehead is discussed below.
- Atopic dermatitis
Atopic dermatitis tends to occur in people who have an allergic disposition. It often starts early in life and is linked to other allergy-related conditions like allergic rhinitis and allergic asthma. The immune system reacts to the presence of certain harmless substances (allergens) resulting in inflammation. It is believed to be due to an interplay of genetic factors and environmental factors, although the exact reason why it occurs is unclear. Atopic dermatitis is what most people refer to as eczema, or sometimes as infantile eczema (baby eczema).
- Seborrheic dermatitis
Seborrheic dermatitis is a condition associated with excessive sebum (skin oil) that leads to inflammation of the skin. The exact cause is unknown but it is believed to be due to a reaction to the Malassezia yeasts on the surface of the skin. Seborrheic dermatitis is not an yeast infection of the skin. The condition tends to occur in the areas of the skin where there are more sebaceous glands, like the face, forehead and scalp. It is also known as cradle cap in infants and is one of the conditions that is commonly termed as dandruff in adolescents and adults.
Picture of scalp seborrheic dermatitis.
- Contact dermatitis
Contact dermatitis is a common skin condition where there is inflammation due to contact with irritants or allergens. It gives rise to the two types, irritant contact dermatitis and allergic contact dermatitis. In irritant contact dermatitis, some substance irritates the skin and eventually leads to skin inflammation (dermatitis), example shampoos and other hair care products. With allergic contact dermatitis, an otherwise harmless substance triggers an immune reaction in the skin resulting in inflammation, like in hair dye allergies.
Picture of contact dermatitis.
Thickening of the skin and darkening (hyperpigmentation) are the central features of acanthosis nigricans. It tends to affects the skin folds, like the neck, armpits and groin, but the forehead is also frequently affected. It may also occur on the eyelids. The exact cause is unclear but the condition seems to be associated with obesity and type 2 diabetes mellitus. There may also be a genetic component to the condition. Some cases of acanthosis nigricans has been liked to cancers or certain drugs like hormone medication.
There are several types of psoriasis but the most common is psoriasis vulgaris which is a chronic inflammatory skin condition. It is a result of skin overgrowth without rapid shedding of the skin cells thereby resulting in thickened skin lesions. One of the sites that is commonly affected is the head and scalp psoriasis often extends on to the forehead. The inflammation is believed to be due to an immune-mediated reaction which is triggered by genetic and environmental factors, although the exact cause is unknown.