Streptococcal intertrigo is a skin condition that is secondary to a streptococcal bacterial infection. It is often seen in infants and young children and can be characterized by a fiery-red color of the skin, foul odor with an absence of satellite lesions, and skin softening (due to moisture) in the neck, armpits or folds of the groin. : 262  Newborn children and infants commonly develop intertrigo because of physical features such as deep skin folds, short neck, and flexed posture. Prompt diagnosis by a medical professional and treatment with topical and/or oral antibiotics can effectively relieve symptoms. Etiology
The main causes of intertrigo are mechanical factors, such as heat and maceration of the skin, and secondary infections, which mostly happens due to moisture build-up in the skin folds, making those areas ideal feeding places for secondary bacterial and fungal infections. A lot of cases of this disease are seen in individuals with diabetes mellitus since they have higher pH levels in their skin folds because of their condition. Given these reasons mentioned above, there have been higher cases of intertrigo in individuals with obesity, diabetes mellitus, immunodeficiency secondary to virus infection, large skin folds, are bedridden, or wear diapers that trap moisture (i.e. babies or older adults using incontinence supplies). Signs and symptoms
Streptococcal intertrigo commonly presents with a beefy-red, smooth, shiny lesion that has well-defined borders. There are no satellite lesions surrounding the area, and a distinct foul smell is common. The infection may be accompanied by general malaise and a low-grade fever.
Group A streptococci have surface molecules of lipoteichoic acid and protein F which aid in the adhesion to host cells. Once adhered, it releases streptolysin and hyaluronidase to further degrade host tissues, enabling a deeper colonization. In addition to attachment and dissemination factors, Group A streptococci are also encapsulated and have other varying protein factors that defend it from host immunity. Mechanism
The most common symptom associated with streptococcal associated intertrigo is erysipelas, an infection of the upper or superficial layers of the skin. This infection is mostly associated with group A beta-hemolytic streptococcal bacteria (GABHS) since they are normally found in the skin flora. This group of bacteria typically invades and affects the lymphatic vessels, often leading to a localized inflammation. The infection can be recognized by tongue-like or irregular extensions of the rash, accompanied by systemic symptoms such as fever, chills, or a general feeling of discomfort. Once in the lymphatic system of the host, GABHS can easily disseminate systemically to produce effects. Risk Factors
Streptococcal intertrigo occurs when bacteria penetrates the skin. Having an increased amount of skin folds can increase the risk of skin abrasion and erosion, leading to inflammation. Therefore, individuals with obesity, infants, and other factors that increase ones own skin-to-skin contact have an increased risk of intertrigo. Immunocompromised individuals are also at a greater risk for intertrigo since they are more susceptible to infection from any foreign pathogen. Environmental factors also play a role in increasing the risk of this condition.