Neck Rash on a Five-Month-Old Baby

Rashes are a very common condition that can affect the soft and smooth skin of young infants. They can be caused by a number of factors, including infections and reactions to environmental stimuli or, more rarely, be the sign of serious disorders. Rashes can show up in different areas of the body but more frequently appear in the diaper area, trunk, face and neck. A rash appearing on the neck of a 5-month-old baby can be indicative of a number of conditions. A reader should first contact her child's pediatrician for advice.


Infant intertrigo is a red rash that appears on the skin of many babies. It mostly develops due to the accumulation of moisture in the fat folds of the neck. This area is often difficult to keep clean and dry because breast milk, formula and food are easily trapped there. When bathing your child, make sure to clean the area with soap and rinse accurately with water. Pat dry and do not apply any baby oil or other products directly on the broken skin. Intertrigo sites can provide a favorable environment for bacterial and fungal infections, so seek medical advice if you notice a change in odor.

Heat Rash

During the hot summer months, an infant can develop small pimples and blisters in proximity of the folds of her neck. This condition is known as heat rash and manifests as a consequence of overheating and sweating. The easiest way of improving a heat rash is to cool down your baby by removing excess clothing. After bathing, allow the area to air-dry, or gently pat dry with a cotton cloth. Apply a good-quality diaper rash cream. Heat rashes are not serious conditions and usually disappear in a few days 12.


Eczema, or atopic dermatitis, is a rash characterized by red, scaly and thickened patches. It can develop in the neck as well as other body sites, such as the face, the hands and the back. The exact causes of eczema are unknown, although the condition is often inherited. To soothe your baby, keep his neck area from becoming too dry by giving daily baths. Only use mild and fragrance-free soaps, avoid sudden temperature changes and keep his fingernails as short as possible to prevent scratching.

Sixth Disease

The appearance of a rash in the neck of an infant can also be due to a viral disease known as roseola infantum, or sixth disease. Small pink spots that turn white upon pressure can develop subsequently to a fever between 102 and 105 degrees F. The rash can also appear on the back and upper arms. Irritability and loss of appetite are other symptoms that may accompany the illness. There are no treatments against the infection causing sixth disease, but a child can be kept comfortable by providing plenty of fluids and treating the fever when necessary.