Most skin disorders can also occur in the inguinal and genital area.
Good history taking and examination of other skin areas form the cornerstones of correct diagnosis.
Histological examination is important if response to treatment is poor or a skin malignancy is suspected.
Avoid overdiagnosis and treatment of Candida infections.
History and examination
Many common skin disorders occur in the genital area that may be difficult to differentiate based on the clinical picture alone.
Is there any history of skin disorders? Is there a family history of atopic eczema, for example?
Does the patient have any diagnosed contact allergy? Has the patient reacted to skin care or hygiene products or haemorrhoid medication, for example? Recurrent or intermittent symptoms associated with topical treatment suggest an allergic aetiology.
Are the lesions itchy (atopic eczema, allergic contact dermatitis)?
Sex life; is a venereal disease possible?
Does the patient have pain or general symptoms (infections)?
Skin lesions should be examined close-up, too, paying attention to the following:
location (symmetricity, unilaterality, etc.)
other areas (scalp, other skin, nails, ears, etc.).
Before seeing a doctor, many patients may have treated their symptoms with various prescription-free topical medicines, which may distort or complicate the clinical picture.
Nappy-age children
Nappy rash is the most common condition. Round erosions (craters) may be present in severe nappy rash but erythema and papules are the usual presentation (picture 1). Atopic dermatitis is not usually seen in the nappy area.
Detecting yeast (Candida albicans) on the skin does not prove its causative role. In genuine candidiasis there are usually satellite lesions around a primary (severely affected) patch of confluent erythema (picture 2).
During the first months of life, seborrhoeic eczema may be fulminant in the nappy area.
Ringworm (dermatophytosis) in the inguinal region of children is nearly always a false diagnosis (take a sample for culture!).
Adults
Various types of eczema are most common.
Women
The moist, warm environment in the area of the external genitals and the high permeability of the skin and mucosa predispose women to irritation and sensitization leading to irritant or allergic eczema.
Irritant eczema due to leukorrhoea, vulvitis (e.g. candidal vaginitis, bacterial vaginosis) Vulvovaginitis
Symptoms caused by physiological vaginal discharge (itching, burning and possibly slight erythema at the vaginal introitus and in the pudendal lips)
Irritation due to atrophic vaginitis (vulvovaginitis)
Both sexes
Irritant eczema due to excessive washing (particularly with soap)
Intertrigo (erythema, maceration, sometimes itching in the groin and perianal area); due to poor ventilation, frequent use of panty liners, overweight, underlying diseases, sweating, friction, inadequate hygiene
Atopic eczema (slight scaling and itching, in chronic forms lichenification)
Seborrhoeic eczema Seborrhoeic Dermatitis in the Adult (pictures 34; groin, perineum, anal cleft); clearly defined, erythematous, rather moist patches possibly with fissuring and maceration at the centre, no activity at the margin as in ringworm
Psoriasis Psoriasis presents in the genital area as erythematous, slightly scaly, usually itchy patches (picture 13). However, due to the moist environment, there may be no scaling. In about 2 to 5% of patients with psoriasis, the disease only produces symptoms on genital skin.
Inverse psoriasis (also known as intertriginous or flexural psoriasis) occurs in the groin and anal cleft. Patients may have typical psoriatic patches at some of the typical sites of the disease, i.e. elbows, knees or scalp.
Possible causes: haemorrhoid or skin care products, additives used in rubber production, topical antifungal medicines. Condom users may become sensitized to latex.
Lichen sclerosus et atrophicus causes clearly defined light patches on the skin and mucosa of the external genitals and the perineum.
The clinical picture may additionally include haematomas and blood blisters. The primary symptom is usually severe itching getting worse towards the evening.
Untreated, the disease may progress to labial atrophy and shrinkage of the introitus (kraurosis vulvae, picture 14), which may lead to dyspareunia.
In men, the disease may present as chronic balanitis.
Various types of lichen ruber planus may be seen in the genital area (picture 15).
The most severe clinical picture is erosive lichen ruber planus of the mucosa, which may cause bloody discharge, burning and pain. In bimanual pelvic examination the mucosa bleeds easily, and there are clearly defined erythematous lesions on the vaginal wall.
The erosive form of disease is often chronic, painful and resistant to treatment.
Other skin problems
In the genital area there is often neurodermatitis caused by a chronic cycle of itching and scratching. The triggering factor may be a skin disorder or candidiasis in the area.
Candidal intertrigo (indistinctly defined, weeping erythema with satellite papules, rapidly recurring genuine candidiasis) is an indication for checking the patient's blood glucose and immune status.
Erythrasma (clearly defined, mild erythema caused by Corynebacteria, usually asymptomatic; pictures 1617)
Hidradenitis suppurativa (recurrent abscesses and scarred lesions in flexural areas, particularly the groin and armpits) Hidradenitis Suppurativa
Herpes simplex infection Genital Herpes (pictures 1819). Primary infection usually bilateral, with blisters and ulceration; may cause fulminant disease. In recurrent cases unilateral with a milder course of disease.
Pubic lice (phthiriasis pubis) Head Lice and Pubic Lice. Use a magnifying glass (or stereomicroscope): nits can be seen, sometimes also lice. Also examine the eyelashes.
Papules on the penis and scrotum (picture 20) are typical for scabies Scabies. Examine the wrists and interdigital folds of the fingers.
Abscesses Skin Abscess and Folliculitis commonly occur in the genital area: painful erythema with fluctuating, palpable nodule deeper inside and suppuration.
Erysipelas and cellulitis Erysipelas: clearly defined, hot erythema, often bilateral, in the scrotum, for example; fever, elevated infection parameters
Keep in mind premalignant lesions of the genital area (leukoplakia) and the possibility of malignant lesions (e.g. vulvar carcinoma, carcinoma in situ).
Extramammary Paget's disease (EMPD): clearly defined, often unilateral lesion with macerated appearance, unresponsive to treatment. If unilateral inguinal dermatitis remains unchanged or expands in spite of treatment, take a biopsy.
Workup
Samples for microscopy and fungal culture are required if ringworm is suspected.
Keep in mind that yeast (such as Candida albicans) found by culture usually represents colonization. Candidiasis is overdiagnosed.
Bacterial and fungal culture results should be interpreted critically. Contamination and colonization are common.
Blood glucose should be determined as necessary to exclude diabetes.
If there is vaginal or urethral discharge, chlamydial and gonococcal samples should be taken (detection of C. trachomatis and N. gonorrhoae nucleic acid in urine).
In the case of vulvovaginitis or irritant contact dermatitis due to vaginal discharge, yeast culture or microscopic examination (to examine yeast, Trichomonas and clue cells) can be performed.
It is important to take a biopsy of the rash area if the diagnosis is not clear, if response to treatment is poor or if you wish to exclude the possibility of a malignant skin lesion.
Histological examination is useful if you suspect psoriasis of the skin, lichen sclerosis et atrophicus or lichen ruber planus, as each has specific histological features.
If the lesion is unilateral, weeping and poorly healing, it is important to exclude malignancies of the skin, such as carcinoma in situ, genital carcinoma or Paget's disease.
Epicutaneous tests may be indicated if allergic contact dermatitis is suspected.
Treatment
Good basic care should be used to prevent irritation (avoiding strong detergents, irritating topical care products and tight synthetic underwear, and regular use of non-medicated ointments).
Moisturizing non-medicated ointments or skin care oils should be applied to the genital and perianal skin. Too frequent washing and use of soap should be avoided.
Causal treatment, if possible (e.g. patients with irritant contact dermatitis should reduce the use of tight clothes and panty liners and stop epilation, and patients with allergic contact dermatitis should avoid the triggering factor)
Ringworm of the groin is treated with topical terbinafine for 1-2 weeks or an azole preparation for 3-4 weeks. In a severe case that reaches deep into the hair follicles, the topical drug is combined with systemic drug therapy for a period of 1-4 weeks Dermatomycoses.
Irritant contact dermatitis and intertrigo can be effectively treated by applying a powder (e.g. talc or miconazole powder) or zinc oxide paste in the morning after washing; in the evening, after washing apply an extemporaneously compounded mild glucocorticoid ointment mixed with sulphur (prescribe: hydrocortisone 1.0%, medicinal sulphur 2.0%, make up to 100.0% with non-medicated ointment), as necessary.
In eczema, the treatment of first choice is mild topical glucocorticoids intermittently in courses of 1 to 2 weeks, for example. If necessary, you can prescribe extemporaneous addition of 2 to 3% of sulphur, e.g. 2.0% medicinal sulphur made up to 100.0 g with non-medicated cream.
Topical calcineurin inhibitors (tacrolimus and pimecrolimus ointments) are also quite effective in the treatment of atopic eczema, often also other types of eczema and genital psoriasis.
Mid- to high-potency (Class II-III) glucocorticoid ointments in courses of, for example, 2 to 3 weeks are needed to treat neurodermatitis and lichen sclerosus et atrophicus. In cases that are extremely difficult to treat short courses (e.g. 2 to 3 weeks) of superpotent (Class IV) glucocorticoid ointments applied once daily at night can be prescribed.
Not all products meant for the treatment of psoriasis can be used for psoriatic lesions in the genital area; primarily low- to midpotency (Class I-II) glucocorticoid ointments should be used for topical treatment.
Specialist consultation
A dermatologist should be consulted in cases of severe genital eczema resistant to treatment.
Epicutaneous tests should be performed if allergic contact dermatitis is suspected.
If gynaecological causes are suspected, a gynaecologist should be consulted.
References
Moyal-Barracco M, Wendling J. Vulvar dermatosis. Best Pract Res Clin Obstet Gynaecol 2014;28(7):946-58. [PubMed]
Doyen J, Demoulin S, Delbecque K et al. Vulvar skin disorders throughout lifetime: about some representative dermatoses. Biomed Res Int 2014;2014():595286. [PubMed]
Doyen J, Demoulin S, Delbecque K et al. Vulvar skin disorders throughout lifetime: about some representative dermatoses. Biomed Res Int 2014;2014():595286. [PubMed]