Introduction

Definition of intertrigo

Intertrigo also known as intertriginous dermatitis is an inflammatory condition of skin folds caused by skin-on-skin friction (where the surface of the skin rubs against each other). It is caused by irritation by heat, moisture, maceration, friction and lack of air circulation. Intertrigo is made by the combination of two Latin words, inter (between) and terere (to rub), that explains the physiology of the condition.¹ The moist damaged skin is prone to secondary (fungal) infections, mainly by Candida (fungus) species. However other bacterial, viral or fungal infections may also occur. Intertrigo can affect people of any age group and commonly affect the groin, axilla, perineum, inframammary creases and abdominal folds. Unusually, it can also affect the neck creases and interdigital areas. Particularly, the lesions are erythematous patches of various intensity with secondary lesions appearing as the condition progresses.²

Prevalence in older adults

Ageing is associated with a number of skin changes, which cause an increase in the skin surface pH and a decrease in the skin barrier function, increasing the chances of a wide range of age related skin conditions. Increase in the skin surface pH promotes the instance of candida skin infection. Dryness of the skin is also a very common problem in older adults which is generally associated with decreased moisturisation and transepidermal water loss. However, whether these intrinsic skin conditions are associated with intertrigo in the older population is unclear, but it seems older age to be associated with intertrigo.³

Importance of addressing intertrigo

If intertrigo is not treated properly it leads to different complications depending upon the area involved. If a fungal infection between your toes or fingers is left untreated it can also cause fungal infection in your toenails or fingernails. Generally, in diabetic patients, it reaches the deeper layers of the skin and causes cellulitis and it can be life-threatening. Even few untreated intertrigo cases have the chance of developing into a medical emergency called sepsis, a serious condition in which the body responds improperly to an infection that may progress to septic shock when there is a sudden drop in blood pressure that can damage the lungs, kidneys, liver, and other organs.⁴

Understanding intertrigo

Causes and risk factors

Intertrigo caused by skin-on-skin friction, where the surface of the skin rubs against each other, leading to inflammation of the epidermis. Moreover, flexural surfaces (the part of the body that bends or folds) have a higher surface temperature compared to other body parts. Furthermore, moisture builds up in the affected intertriginous areas and develops a feeding ground for secondary infections to flourish, especially candida species as they develop in heated and high-moisture environments. 

So heat and maceration play an important role and make it easier for secondary infections, in cases of intertrigo, to develop.⁵ It can be caused by a variety of gram-positive or gram-negative bacteria or fungi, including various yeasts and dermatophytes. 

Common signs and symptoms

Signs and symptoms of intertrigo depend on the severity of the condition. Symptoms of intertrigo at the initial stage include:⁶

• Red or reddish-brown rash where your skin rubs against itself
• Itching, stinging and/or burning sensation
• Feeling pain or uncomfortable in the affected area

If intertrigo is not treat at the initial stage, you can develop the following symptoms:⁷

• Having the feeling that the affected skin is raw
• Visible cracks on your affected skin
• Bleeding at the affected area

Symptoms of intertrigo with an infection can include:

• Presence of foul smell in the affected area
• Having tender and raised bumps on your affected area
• Affected skin may contain pus

Diagnosis and assessment

Clinical manifestations are generally enough to diagnose intertrigo in which healthcare providers gather important information to make the correct diagnosis by considering valuable observable symptoms. The type of lesions (e.g., erosions, vesicles, pustules, nodules, papules, plaques, macules) can indicate the type of disorder present.¹ 

The culture of the lesion is taken if a bacterial infection is suspected. However, Wood's light examination helps to identify a Pseudomonas or erythrasma infection better than a culture. Wood's light specifically gives green fluorescence with Pseudomonas infection and coral-red fluorescence with erythrasma. If a fungus is responsible for the secondary infection, it can be identified by a skin scraping of the lesion. A scraping should be taken from the active portion of the lesion and 20% potassium hydroxide (KOH) solution should be added. The presence of hyphae and/or budding yeast, when viewed with light microscopy, indicates a fungal infection.⁸

Impact on older adults

Physical effects

Intertrigo is common among older people. As people age their skin undergoes different changes, like increase in skin pH and decrease in the skin barrier function increasing the susceptibility to a wide range of age-related skin conditions.⁹ For example, the higher skin pH can encourage fungal skin infections, particularly in areas where skin folds overlap, which is more common in diabetic patients. 

Additionally, skin dryness is also a common problem in aged and geriatric patients, linked to reduced hydration levels in the outermost skin layer and less water loss through the skin.¹⁰ However, it remains uncertain whether these natural skin changes, along with other factors like demographics and functional abilities, contribute to intertrigo in the elderly population.³

Prevention and management strategies

 The following are ways to prevent and manage intertrigo:

• As it is prompted by heat, moisture, maceration, friction and lack of air circulation, keeping the affected area dry and exposed to air can help to prevent recurrences.⁶
• Use a soft towel for proper drying after bath or shower.
• Encouraging weight loss is advisable if obesity is a contributing factor in intertrigo.
• Reduce the skin exposure to urine and stool to minimum, which are the contributing factors in skin maceration and irritation.
• Prefer to work in air-conditioned environments because it will help in the prevention of the rash.
• Patients should be advised to wear loose, light clothing made from absorbent natural fabrics (e.g., cotton) to wick perspiration away from the skin
• Maintain a structured skin care routine like cleansing and moisturising. Ideally cleansing should be with a no-rinse pH-balanced cleanser, avoiding the use of alkaline soaps, if possible. In older patients, application of a skin barrier protectant is advisable.¹¹
• Patient education plays an important role as self-management is a very important aspect to manage the problem like placing cloth, tissue, pads and gauze in the skin folds. Also using powder carefully to absorb moisture will be helpful, although no direct evidence to support this could be found. Absorptive powders, such as talc or cornstarch, are not recommended to be used.¹² Absorbent powder and wet tea bags are other preventive measures that have been proven to be effective.
• Achieving good glycemic control in diabetes is advisable because it is considered a predisposing factor.

Treatment approaches

To treat intertrigo properly, it is important to understand the causative factor that is responsible for the condition, so it can be reduced or removed. Depending upon underlying factors the treatment involves:

• At the initial stage, moisture is responsible for the condition, so use of drying agents such as antiperspirant can be used to minimise the moisture. Triple paste, composed of aluminum acetate solution, zinc oxide, and petrolatum, is an effective antiperspirant that also reduces frictional exposure and improves skin irritation.¹
• Absorbent diapers are effective in decreasing moisture if treatment is required. Petroleum ointment or cream is also an effective and safe option.
• If the rash is due to an infection component, then proper antimicrobial drugs should be prescribed.
• Oral medicine like flucloxacillin or erythromycin should be prescribed as these medicines are effective against gram-positive bacteria, notably Staphylococcus or Streptococcus
• Mupirocin or bacitracin can be used topically if the lesion is infected with a bacteria.
• For resistant fungal infections use oral fluconazole 100 to 200 mg daily for seven days. 
• Clotrimazole, ketoconazole, and oxiconazole ointment or cream are effective treatment options for yeast or fungal-infected intertrigo.¹³
• For candidal intertrigo use of topical nystatin is advisable.
• If highly required, low-dose steroid-like hydrocortisone cream can be used for inflammatory conditions.

It is important to consult with a qualified doctor and discuss the best treatment options before using any of the above-mentioned medications.

Summary

Intertrigo, characterised by inflammation in skin folds due to friction, moisture, and heat, is a significant concern, especially among older adults. The condition can lead to various complications, including secondary infections and even life-threatening situations like sepsis. Prevention strategies focus on keeping the affected area dry, maintaining proper hygiene, and wearing breathable clothing. Treatment approaches range from addressing moisture with drying agents to using antimicrobial drugs for infections. Understanding the underlying factors contributing to intertrigo is crucial for effective management.