Neck Rash (Redness) Causes and Pictures
Redness of the skin anywhere in the body points to two possibilities – the area is irritated or inflamed, or there is flushing. The skin of the neck is no different. While people with a lighter complexion may have a redder appearance of the skin, the reason why skin redness occurs applies to all complexions. Redness is a result of the tiny blood vessels under the skin surface being wider and having more blood flowing through it.
Meaning of A Red Neck
A red neck simply means that more blood is flowing just underneath the skin that lies in the neck region. The tiny blood vessels here carry blood laden with oxygen and nutrients to the skin cells. It also carries away the carbon dioxide and wastes from these cells. These blood vessels can widen (vasodilation) and narrow (vasoconstriction) as required to cater for the metabolic demands of the cells.
The blood vessels will also widen and narrow for other reasons. Some of these reasons are normal changes dependent on a host of factors like the environmental temperature. It is then said to be due to physiologic causes. However, when the widening or narrowing occurs due to disease processes then it is said to be due to pathologic causes. Whatever the cause, redness is primarily due to widening of the blood vessels allowing more blood to flow just under the skin of the neck.
Less often, redness can be due to a burst blood vessel where small amounts of blood empties out and collects in the tissue of the skin. It is known as hematoma. Eventually this blood will turn a dark red to purple and brown color. The lighter a person’s skin color, the more visible the changes in blood flow be it physiologic or pathologic. Often there are other symptoms that may accompany this redness, such as swelling, burning, pain, itching and heat over the affected area.
Causes of Neck Redness
Physiologic changes in blood flow occurs with:
- Hot weather where the blood vessels dilate to dissipate heat into the environment.
- Alcohol consumption and with the use of certain illicit substances and prescription drugs.
- Eating spicy foods or with drinking caffeinated beverages.
- Strong emotions, like anger.
- Hormonal changes like during pregnancy or menopause.
In most of these cases the redness occurs without other skin symptoms like itching, burning, swelling and so on. However, with pathologic causes there are usually other skin symptoms that we often collectively refer to as a rash. It is a result of inflammation where inflammatory chemicals are released at the site. This causes the blood vessels to widen (redness and heat), become leaky so that fluid can empty out into the tissue spaces (swelling) and for specialized receptors at the site to become activated (burning, pain or itching).
Allergies
An allergic reaction is one of the common reasons for neck redness. It occurs when there is contact with an otherwise harmless substance that incorrectly triggers immune activity. If it is localized when the skin on the neck comes into contact with an allergen then it is known as allergic contact dermatitis.
This may occur with an allergy to certain textiles, skin creams or other substances that make contact with the skin, and often with an allergy to certain metals found in neck jewelry. Sometimes the allergic reaction is systemic in that it occurs throughout the body when the allergen is ingested or inhaled.
Picture of allergic contact dermatitis
Infections
An infection of the skin of the neck is not uncommon. It can be caused by a number of infectious agents although most are due to bacteria, viruses or fungi. Bacterial infections may be limited to the skin of the neck (impetigo) or affect just a hair follicle (folliculitis). If it extends deeper into the subcutaneous tissue (cellulitis) then it can be very serious.
Viral infections of the neck skin may be seen in conditions such as shingles, chickenpox, herpes simplex and so on. Fungal infections are common and when it occurs on the neck it is often a continuation of a fungal infection of the scalp (tinea capitis) or the beard area (tinea barbae).
Irritants
Any number of substances can irritate the skin and trigger inflammation even without an allergic reaction. When these irritants come into direct contact with the skin of the neck and triggers a reaction then the condition is known as irritant contact dermatitis.
Detergents, soap, pool chlorine, certain skin applications, constant rubbing of clothing against the skin (chaffing) and so on can all irritate the skin. However, it is often not realized that even harmless substances can irritate the skin like water and a person’s own sweat if it is on the skin for too long.
Other Skin Diseases
- Rosacea is a skin condition where there is extreme redness of the skin often with pus-filled blisters. It is a chronic condition that tends to affect women with lighter skin complexions. The cause is unknown but alcohol, spicy food, hot weather, sunlight and stress tends to trigger or worsen the condition. The face is more commonly affected.
Picture of rosacea on the cheek
- Atopic dematitis, often referred to as eczema, is a condition that often arises in childhood. It often occurs with other conditions like asthma and allergic rhinitis (hay fever). Redness, dry skin and itching are the main symptoms and it most often affects the folds of the body, like elbows, behind the knees, behind the ears, and the neck.
Picture of atopic dermatitis on the neck - Acne vulgaris is a common condition especially among teens. It occurs when the follicles become blocked with oil plugs and then may become infected. Skin redness and pimples are the main symptoms. It usually affects the face, scalp, shoulders and chest but can also occur on other areas like the neck.
Picture of acne of the back which can extend to the neck - Heat rash (miliaria or prickly heat) is a skin condition that is mainly seen in infants and young children but may also affect adults. It occurs when the sweat ducts become obstructed. As a result perspiration produced in the sweat glands are trapped under the skin and gives rise to a the fine bumps seen in heat rash.
Picture of miliaria (heat rash) on the back
- Psoriasis is a chronic skin condition where there is inflammation and thickening of the skin. It is an autoimmune condition where the skin cells do not slough off as it should. There are different types of psoriasis, with psoriasis vulgaris being the most common. The lesions appear as thick red to silvery white plaques.
Picture of scalp psoriasis which can extend to the neck - Seborrheic dermatitis is an inflammatory skin condition that occurs for unknown reasons. There is excess oil (sebum) production leading to a yellow scaly skin lesion that may crust and flake off. The oily areas of the skin like the scalp and face are more commonly affected.
Picture of seborrheic dermatitis on the neck
References
Pictures sourced from Dermatology Atlas Brazil (atlasdermatologico.com.br).
Last updated on September 7, 2018.
