Intertrigo is the word used to describe a rash in body folds. Affected skin is reddened and uncomfortable. Intertrigo is particularly common in those who are overweight.
Body folds (flexures) are prone to inflammatory rashes because of:
- Relatively high skin temperature
- Moisture from insensible water loss and sweating cannot evaporate
- Friction from movement of adjacent skin results in chafing
Bacteria and yeasts which are normally resident on the skin multiply in such environments and may result in further damage to the skin.
- Thrush, caused by yeasts such as Candida albicans, is characterised by rapid development, with itchy moist peeling white skin with small peripheral pustules
- Erythrasma, caused by Corynebacterium minutissimum, results in persistent brown patches
- Tinea pedis (athletes foot), caused by dermatophyte fungi such as Trichophyton rubrum, causes peeling, cracks, and blisters between the toes
- Folliculitis, caused by various bacteria especially Staphylococcus aureus, is often provoked by shaving. Painful red spots and pustules are centred on hair follicles
- Psoriasis, recognised by well-demarcated patches and persistence. In other sites scaly red patches can be found, particularly on the elbows, knees and in the scalp.
- Seborrhoeic dermatitis, which presents with salmon-pink flaking patches, often coming and going in scalp, behind ears, on the mid face and other skin creases.
- Atopic dermatitis, usually first occurring in infancy. Very itchy dry areas are most often found on elbow creases, behind the knees, and the neck.
- Contact allergic dermatitis and contact irritant dermatitis - irritable rashes caused by materials in contact with the affected area, eg. antiperspirant.
Less common causes of intertrigo include:
- Blistering skin disorders such as bullous pemphigoid
- Rare inherited conditions such as Hailey-Hailey disease
- Miscellaneous other conditions, including granular parakeratosis.
to candida infection
to seborrhoeic dermatitis
Investigations may be necessary to determine the cause of intertrigo.
- A swab for microscopy and culture of micro-organisms (bacteria)
- A scraping for mycology (fungi)
- A biopsy may be performed if the skin condition is unusual or fails to respond to treatment.
Treatment depends on the underlying cause, if identified, and on which micro-organisms are present in the rash. Combinations are common.
- Sweating may be reduced with a gentle antiperspirant.
- Bacteria may be treated with topical antibiotics such as fusidic acid cream, mupirocin ointment, or oral antibiotics such as flucloxacillin and erythromycin
- Yeasts and fungi may be treated with topical antifungals such as clotrimazole and terbinafine cream or oral agents such as itraconazole or terbinafine
- Inflammatory skin diseases are often treated with low potency topical steroid creams such as hydrocortisone. More potent steroids are usually avoided in the flexures because they may cause skin thinning resulting in stretch marks (striae) and even ulcers. Calcineurin inhibitors such as tacrolimus ointment or pimecrolimus cream may also prove effective.