Intertrigo is a superficial inflammatory skin condition of the skin's flexural surfaces, prompted or irritated by warm temperatures, friction, moisture, maceration, and poor ventilation. Intertrigo's Latin translation, inter (between) and terere (to rub) helps explain the physiology of the condition. Intertrigo commonly becomes secondarily infected, notably with Candida; however, other viral or bacterial etiologies may play a factor in its pathogenesis. Intertrigo can be seen in all ages and is primarily a clinical diagnosis with the frequently affected areas being the axilla, inframammary creases, abdominal folds, and perineum. Characteristically, the lesions are erythematous patches of various intensity with secondary lesions appearing as the condition progresses or is manipulated.
Mechanical factors and secondary infections are the landscape causes of intertrigo. Heat with maceration plays a central role in facilitating this process. The skin folds battle constant frictional forces producing irritation and at times, erosions to the inflamed skin. Further, moisture builds up in the affected intertriginous areas and develops a feeding ground for secondary infection to flourish. Candida species thrive in heated, high-moisture environments and is a common offender of secondary infection in cases of intertrigo. Moreover, patients with diabetes have increased pH levels in intertriginous areas contributing to their demographic prevalence. However, it is not uncommon to see gram-positive and gram-negative bacteria, as well as other fungi and viruses accounting for some of the cases.
People of all ages, from infancy through advanced age, can be affected by intertrigo. The inflammatory condition manifests itself in the infantile age group as a variation of diaper dermatitis. Furthermore, the increased likelihood of a naive or reduced immune system, lack of mobility, and urinary/bowel incontinence contribute to the skin manifestations and its complications. Obesity and diabetes are 2 conditions that increase the frequency of developing intertrigo. The condition is most prevalent in geographic areas that have hot and humid climates. Lastly, there is no race or gender predilection observed with the condition.
Environmental factors and genetic causes play a leading role in the development of intertrigo. One of these factors is the friction caused by adjacent skin surfaces causing inflammation of the epidermis. Moreover, flexural surfaces have a higher surface temperature comparable to other body parts. The moisture and sweat build up that gets trapped in these areas add to the maceration of the stratum corneum and epidermis. Nonetheless, the integumentary system houses bacteria and yeast that flourish in this environment and overgrow in these conditions, making infection a common finding.
There is no characteristic histologic change seen in intertrigo. Some cases can present with mild spongiosis visualized in the epidermis.
The presentation of intertrigo is generally a chronic subtle onset of pruritus, burning, tingling, and pain in the skin folds and flexural surfaces. If there is an acute change in the quality of the symptoms, consider a secondary infection with Candida albicans, bacteria, or other pathologic organisms. Likely, the patient will be involved in an activity that involves rubbing of their skin surfaces together. Hot and humid environmental conditions are also aggravating conditions that contribute to the pathology. Therefore, intertrigo tends to see a higher rate of seasonal incidence. Hyperhidrosis, seen with strenuous exercise, is a prominent contributing factor in the inflammatory condition. Predisposing factors such as obesity and diabetes, as well as signs of incontinence, urethral discharge and draining wounds on exam all contribute to the warm, moist occluded environment responsible for the development of intertrigo.
On physical examination, prevalence is highest among obese patients, yet all body mass index (BMI) subclasses are implicated dependent on other factors. The increased surface area in obese patients accentuates the folds and creases of the body suitable for higher body temperatures. The initial presentation on the skin exam is a mildly erythematous patch on both sides of the skin fold. The degree of inflammation is dependent upon factors such as location and duration, as well as if there is a secondary co-infection. Over time, the erythematous patch can develop erosions, macerations, fissures, crust, and weeping from the site. If a pustule, crust, or vesicle is visible, secondary infection should be considered. If Candida species are suspected, satellite papules and pustules are pathognomic. Bluish-green tint will indicate infection with Pseudomonas. Bacterial intertrigo tends to weep and is an intensely erythematous and potentially tender lesion. In interdigital intertrigo, Trichophyton rubrum, Trichophyton mentagrophytes, and Epidermophyton floccosum are the implicated organisms in this body region.
Further evaluation beyond the clinical diagnosis may be required to determine the exact cause and most effective treatment modality. The lesion can be cultured if a bacterial origin is suspected. Fungus, another common invader, can be elicited by a skin scraping of the lesion. If the presentation is unusual or therapy has failed, consider performing a biopsy.
To properly treat intertrigo, it is imperative to recognize the underlying factor that is causing the condition. Therefore, one should reduce or remove the offending causative factor or agent discussed above. If there is an infectious component to the rash, then the proper antimicrobial should be administered. In simple intertrigo, drying agents such as antiperspirants can be used to minimize the sweating. A bath with proper drying using a soft towel should follow excessive physical activity that causes excessive perspiration. Aluminum acetate solution, zinc oxide, and petrolatum, the ingredients that comprise triple paste, is an effective antiperspirant that also reduces frictional exposure and improves skin irritation. Staying cool by wearing loose clothing, and working in air-conditioned environments will help in the prevention of the rash. Absorbent powders compress with an aqueous solution of aluminium triacetate 1:40, and wet tea bags are other preventative measures that have been proven to be effective. Absorbent diapers are more effective at decreasing the moisture; however, if treatment is required, petrolatum ointment cream is effective and safe for diaper dermatitis. If the lesion is infected with a bacteria, then use a topical treatment such as mupirocin. If oral medication is required, an effective option against gram-positive bacteria, notably Staphylococcus or Streptococcus, like flucloxacillin or erythromycin should be prescribed. Topical clotrimazole is an effective treatment for yeast or fungal infected intertrigo. Low-dose steroids may be initiated for anti-inflammatory properties, for example, hydrocortisone cream, yet it is not always needed. A lower strength steroid should be preferred if chosen to prevent atrophy in the already thinner epidermis of the flexural surfaces.
The differential is quite extensive for intertrigo. Many other conditions present in the flexural surfaces. However, infection is most important to rule out, and the proper infectious agent should be sought out to provide the correct antimicrobial therapy necessary to eliminate the offending agent. Bacteria, viruses, dermatophytes, and candidal organisms can all cause intertrigo or provoke a secondary infection. Once infection is ruled out, other similar presenting conditions commonly found in the flexural surfaces can be further investigated. More common conditions such as seborrheic dermatitis, irritant or allergic contact dermatitis, atopic dermatitis, inverse psoriasis, pemphigus, scabies, metabolic derangements, and malignancies frequently present in the skin fold mimicking intertrigo. Nonetheless, intertrigo remains a clinical diagnosis with the findings and clinical picture described above.
The prognosis is positive for the majority of patients. The underlying risk factors should be addressed to diminish the intertrigo outbreaks. However, if the risks such as diabetes and obesity are not properly managed, the condition tends to relapse quite frequently.
The complications that can arise with intertrigo are predominantly secondary infections that have been discussed at length above. To optimize prevention of infection, the rash should be directed to a physician, primarily a dermatologist to properly manage the condition. If left untreated, the rash can develop into cellulitis. Furthermore, sepsis can result from hidden ulcers that develop in patients without supervision or obese individuals. Contact dermatitis can occur secondary to topical agents used to treat the rash. Also, prolonged steroid use can cause atrophy and striae to the thinned epidermis of the flexural surfaces.
Whether it is the pediatrician or adult primary care physician, if there is a doubt of suspicion or a rash that has failed treatment, a dermatologist should be consulted to manage the condition further.
Topics that should be discussed with the patient and their family is weight loss and weight control, proper hygiene, glycemic control in patients who have diabetes, and measures to reduce the frictional component of skin to skin contact.
Often, there is a combination of an infectious and inflammatory component. To delineate the 2, infections are often unilateral and asymmetrical. Inflammatory disorders tend to be symmetrical a majority of the time.
Physicians, nurses, and pharmacists all play an optimal role in achieving successful clearance of the rash. Physicians and nurses need to emphasize and educate the preventative risk factors and management of the rash to clear the current and prevent further intertrigo occurrences. The physician can consult the pharmacist when necessary to help with varying formulations of topical therapy as well as oral for certain infectious etiologies.