Dermatology: Common presentations in primary care

An overview of the most common dermatology presentations seen in general practice

Dermatological conditions affect between 30-and-70 per cent of people worldwide and are the most frequent reason for consultation in general practice.² An estimated 54 per cent of the Irish population is affected by skin problems annually, and up to 33 per cent could benefit from medical care at any one time. An estimated 15-to-20 per cent of GP consultations relate specifically to dermatology. In Ireland this represents between 712,500-and-950,000 GP consultations for dermatological conditions each year.¹

Many skin conditions can be managed in primary care and approximately 65,000 referrals occur annually to specialist dermatology departments for more complex forms of skin disease. Some of the most common skin diseases are increasing in frequency, with over 230 skin cancer-related deaths in Ireland annually. Approximately 50 per cent of referrals to dermatology are for skin cancer. The impact of skin diseases on quality-of-life can be profound, and many non-cancerous inflammatory skin diseases are chronic in nature.¹

More than 2000 dermatological entities are listed in the International Classification of Disease (ICD 11), including rare or novel skin diseases, however, a small number account for most of the disease burden. These include inflammatory conditions such as eczema, psoriasis, acne, and rosacea; skin cancers; autoimmune conditions such as lupus and vitiligo; and hereditary diseases.^{2, 5, 6}

No complete data on the prevalence of skin diseases across European countries is available. To estimate the prevalence of the most frequent skin conditions or diseases in 27 European countries (24 EU countries, plus Norway, Switzerland, and the UK (NEUKS)), a study using a population-based approach involving 44,689 participants (21,887 (48.97 per cent) men and 22,802 (51.03 per cent) women) was carried out and published in 2022.² The aim of this study was to evaluate the prevalence of the most common dermatological diseases and conditions of adult patients across Europe. Results showed that 43.35 per cent of the NEUKS adult population reported having had at least one dermatological disease or condition.

The most frequent conditions are fungal skin infections (8.9 per cent), acne (5.4 per cent), and atopic dermatitis or eczema (5.5 per cent). Alopecia, acne, eczema, and rosacea are more common in women, and psoriasis in men. Acne affects mainly young adults, while psoriasis was more frequent in respondents older than 25 years.²

Timely and accurate diagnosis is key to determining the most effective management approaches for dermatological conditions. Depending on the severity of presentation and stage of disease, management ranges from prevention and self-management approaches to a variety of topical and oral medications, steroid injections, biologics, surgical interventions, and treatments such as phototherapy and chemotherapy. There is also a significant role for psychological and social supports to reduce the impact and burden of disease.¹

Long waiting lists for dermatology services exist nationally. Historically, a significant part of dermatology outpatient department workload consisted of benign lesions, which require no treatment, or cosmetic problems. Examined by the National Clinical Programme for Dermatology (RCPI/HSE), exclusion criteria for GP referral to dermatology services unless there is diagnostic uncertainty now includes viral warts and verrucae; molluscum; seborrhoeic warts/keratoses; skin tags; dermatofibromas; spider naevi; epidermal cysts; sebaceous cysts; lipomas; tattoos; xanthelasma; physiological male balding; and melasma.¹

Common dermatological presentations in primary care

Rashes

Rashes and minor skin conditions are very common and can affect people of all ages. They can be troublesome in adults and distressing when they occur in babies and young children. Referral to a dermatologist may be important for making difficult diagnoses and selecting certain treatments, however, many rashes are self-limiting, and most can be diagnosed and treated in primary care. Referral to dermatology should be used for the highest scope of practice because the workforce is limited, and specialty care is costly.^3,4

Fungal infection: Ringworm

Ringworm (Figure 1A/B) is a common contagious fungal infection caused by dermatophytes and is easily spread following contact with an infected person through skin-to-skin contact, sharing towels, clothing and bed linen. Pets such as cats and dogs can also transmit the infection to humans. Classification is generally by the site of the body affected. The rash appears as a circular lesion with a raised outer rim and paler centre. The most common infections in pre-pubertal children are tinea corporis and tinea capitis, while tinea cruris, tinea pedis, and fungal nail infections such as onychomycosis are more frequently seen in adolescents and adults.⁴ Treatment varies with the site affected. For skin infections topical treatment is the first-line and some products can be purchased over the counter. Scalp ringworm (tinea capitis) is usually treated for a longer duration (two-to-four weeks) with terbinafine. Both the affected person and family members are advised to use an antifungal shampoo (Ketoconazole) twice-weekly for two weeks. Onychomycosis requires a longer course of oral medication before effect is achieved.⁴ 

Fungal infection: Athlete’s foot

Athlete’s foot, or tinea pedis, is an infection of the skin and feet that can be caused by a variety of different fungi (Figure 2). Although tinea pedis can affect any portion of the foot, the infection most often affects the space between the toes. If it is not treated, it can spread to the toenails and cause a fungal nail infection. Information on the treatment of dermatophyte and other fungal infections of the skin is available at:⁷ www.hse.ie/eng/services/list/2/gp/antibiotic-prescribing/conditions-and-treatments/skin-soft-tissue/dermatophyte-infection-of-the-skin/dermatophyte-skin.html.

Eczema

Eczema (frequently called dermatitis) is an inflammatory skin condition occurring in all age ranges, from babies through to older adults. There are different types of eczema, atopic being the most common (Figure 3), which follows a relapsing and recurring course. Diagnosis is made on examination and the patient typically presents with an acutely inflamed, red, sometimes blistered and weeping patches of skin. Although the rash can occur anywhere, common sites are the flexures of the elbows and backs of the knees.⁴

Eczema herpeticum is a dermatological emergency, warranting same day referral or contact with the local dermatology department. Treatment is with aciclovir.⁸

In infected eczema, swelling and a golden crust suggest probable staphylococcal infection. Swabs are not indicated unless treatment failure or atypical species is suspected. Restoring the barrier with appropriate topical steroids and emollients may reduce bacterial superinfection and lessen anti-microbial requirements.⁸ Topical antibiotics should be used for a limited period of under two weeks because of bacterial resistance. They should not be co-prescribed with oral antibiotics for the same reason. Using antibiotics, or adding them to steroids, in eczema encourages resistance and does not improve healing unless there are visible signs of infection.⁸ Bleach baths may reduce the bacterial load on the skin and contribute to reduced numbers of flares. It is recommended as a maintenance antimicrobial measure once or twice a week. During infective
flares it may cause stinging.⁸ Information on the treatment of eczema is available at: www.hse.ie/eng/services/list/2/gp/antibiotic-prescribing/conditions-and-treatments/skin-soft-tissue/eczema/.

Psoriasis

Psoriasis causes patches of skin that are dry, red, and covered in silver scales.

Plaque psoriasis (psoriasis vulgaris) is the most common form, accounting for 80-to-90 per cent of cases (Figure 4). The scales appear on the elbows, knees, scalp and lower back, but they can appear anywhere on the body. The plaques can be itchy or sore, or both. In severe cases, the skin around the joints may crack and bleed.⁹

Scalp psoriasis occurs on parts of or the whole scalp. It causes red patches of skin covered in thick, silvery-white scales. Some people find scalp psoriasis itchy, while others have no discomfort. In extreme cases, it can cause hair loss, although this is usually only temporary.⁹

Nail psoriasis: In approximately half of all people with psoriasis the condition affects the nails, causing them to develop small dents or pits. The nails can become discoloured or grow abnormally, can become loose and separate from the nail bed, and in severe cases may crumble.⁹

Guttate psoriasis causes small drop-shaped sores on the chest, arms, legs, and scalp. The condition often disappears completely after a few weeks, but some people go on to develop plaque psoriasis. This type of psoriasis sometimes occurs after a streptococcal throat infection and is more common among children and teenagers.⁹

Less common types of psoriasis include: Pustular psoriasis, von Zumbusch psoriasis, palmoplantar pustulosis, acropustulosis, and erythrodermic psoriasis.⁹

Treatment depends on the type and severity of psoriasis and the area of skin affected. Treatment often starts with a topical cream applied to the skin, and then stronger treatments if required. Treatment falls into three main categories:⁹

• Topical – creams and ointments applied to the skin.

• Phototherapy – exposes the skin to certain types of ultraviolet light.

• Systemic – oral and injected medications that work throughout the entire body.

Different types of treatment are often used in combination. Referral to a dermatologist may occur if the symptoms are severe.

Lichen planus

Lichen planus is a less well-known rash than eczema or psoriasis, and is more common in adults than children (Figure 5). It is a non-infectious itchy rash, seen as small shiny, reddish raised papules most commonly on the wrist, ankles, elbows, and lower back although it can develop at any site. Lichen planus occasionally affects the oral cavity and may occur alone or in combination with symptoms at another site. It causes burning or stinging and discomfort in the mouth and on examination the mucosa is covered with painless white streaks. There is a more erosive form where painful ulcers occur, which are linked to an approximate 1 per cent risk of becoming cancerous (one-in-100 patients) over a period of 10 years. Resolution can occur spontaneously without treatment. When itching is severe a sedating antihistamine may be needed. A potent steroid cream, eg, Betnovate, can be used and the dose tailored to severity of symptoms, aiming to reduce once improvement is seen. In severe cases, systemic oral steroids can be prescribed (20mg daily for two-to-six weeks). Oral lichen planus can be treated with a topical steroid, but referral to secondary care will be needed when symptoms are severe or response to treatment is inadequate.⁴

Chickenpox

Chickenpox is a highly infectious condition caused by the varicella zoster virus (Figure 6). It is most prevalent in children under the age of 10 years, with over 90 per cent of cases occurring in this age group. Chickenpox is generally a mild illness, but can rarely be fatal in neonates and the immunocompromised, and can have more serious consequences in adults. Spread occurs by transmission from person-to-person by breathing in infected respiratory droplets via sneezing or coughing, or less commonly through contact with weeping spots. The rash develops 10-to-14 days after contracting the infection, but may take longer. The child is often unwell for a couple of days prior to developing the typically itchy rash, with additional symptoms of headaches, loss of appetite and fever. Adults generally have more serious symptoms, and 5-to-14 per cent of adults develop lung problems such as pneumonia, with smokers at greater risk.⁴

Treatment aims to ease symptoms and comprise of a sedating antihistamine and lotion to ease the itching. Paracetamol may be required if feverish, however, ibuprofen is not recommended as there is an increased risk of soft tissue infection. Adults may need antiviral treatment, ideally to commence within 72 hours of onset of the rash to reduce symptom severity. For adults’ acyclovir 800mg is taken five times daily at approximately four-hourly intervals, during waking hours. Treatment should continue for seven days.^4,10

Full HSE treatment guidance is available at: www.hse.ie/eng/services/list/2/gp/antibiotic-prescribing/conditions-and-treatments/skin-soft-tissue/chickenpox/.

Shingles

Herpes zoster, also known as shingles, is a secondary infection that occurs in some individuals as the result of reactivation of the latent varicella zoster virus, usually within a single ganglion (Figure 7). The individual lifetime risk of developing herpes zoster is between 24-and-30 per cent. Although herpes zoster can occur at any age, incidence increases with age. Two-thirds of cases occur in individuals aged 50 years and older and the risk of developing the disease in those aged 85 years and above is 50 per cent. Once the virus activates, it can lead to a painful, blistery rash. Early symptoms of herpes zoster including headache, fever, and malaise, are non-specific and may result in an incorrect diagnosis. These symptoms are commonly followed by sensations of burning pain, itching, hyperesthesia, or paraesthesia. Herpes zoster is diagnosed clinically, typically based on history and symptom presentation. The treatment of herpes zoster has three major objectives; treatment of the acute viral infection, treatment of the acute pain associated with herpes zoster and prevention of postherpetic neuralgia. Early identification and prompt treatment with antiviral drugs and analgesics frequently reduces acute rash and pain and may prevent some complications. Antiviral drugs have been shown to reduce acute pain and rash severity, accelerate rash resolution, and reduce duration of pain. Herpes zoster can be treated with antiviral medications acyclovir, valacyclovir, or famciclovir, most effective when started within 72 hours after the onset of the rash.^13,14 Information on the treatment of shingles is available at: www.hse.ie/eng/services/list/2/gp/antibiotic-prescribing/conditions-and-treatments/skin-soft-tissue/shingles/.¹⁴

Scabies

Human scabies is a parasitic infection and contagious skin condition caused by the Sarcoptes scabiei var Hominis mite, which burrows into the skin and causes severe pruritis, especially at night.¹¹ Human scabies affects all age ranges and causes many infections worldwide each year. There are two types – classical scabies and crusted (Norwegian) scabies. Classical scabies is the more common type and occurs following contact with another infected person. It is commonly seen in overcrowded living conditions where spread readily occurs. Norwegian scabies is rarer, but more severe, and involves hundreds or thousands of mites infesting the host individual. The resulting infection is highly contagious, but differs from classical scabies in that itching is absent or minimal.⁴

Treatment of scabies is recommended for all members of an infected household even if asymptomatic. All members must be treated simultaneously within 24 hours. Bedding and clothing should be washed at a high temperature to destroy the mites. Items that cannot be washed or dry cleaned should be sealed in a plastic bag for at least 72 hours or put in a freezer. Most people with scabies are cured after two applications of scabicide, but itching may continue for a few weeks after successful treatment. This may be relieved using an oral antihistamine and/or a topical steroid. If new burrows appear after a treatment course of two applications, a second treatment course should be considered.^11,12

Treatment failure or recurrence is common, and isolating the cause can help prevent further infection and limit outbreaks in communities. Reasons for treatment failure include not treating close contacts simultaneously, not decontaminating beddings and clothes at the time of treatment, and non-adherence to the treatment regimen. To prevent reinfection, it is important that all members of the household are treated, as well as any sexual partners over the last six weeks, in the case of genital scabies.^11,12. Information on the treatment of scabies is available at: www.hse.ie/eng/services/list/2/gp/antibiotic-prescribing/conditions-and-treatments/skin-soft-tissue/scabies/.

Acne

Acne is a chronic inflammatory skin disease and is one of the most common dermatological problems seen in general practice (Figure 9 A/B). Acne usually occurs at puberty or in early adult life, when there is a surge of hormones, and it is more common in males than females. It can present with inflammatory and non-inflammatory lesions mainly on the face, but can also occur on the upper arms, trunk, and back. Hypersensitivity to fluctuations in hormones causes the pilosebaceous unit to over produce oil, leading to blocked pores called comedones.¹⁵

Grade 1: Comedones are of two types, open and closed. Open comedones are due to plugging of the pilosebaceous orifice by sebum on the skin surface. Closed comedones are due to keratin and sebum plugging the pilosebaceous orifice below the skin surface.

Grade 2: Inflammatory lesions present as a small papule with erythema.

Grade 3: Pustules.

Grade 4: Many pustules coalesce to form nodules and cysts.¹⁵

First-line treatment of acne is to tackle the excess oil and comedones. It is advisable not to scrub the skin or use astringents as these may rupture the comedones and promote inflammatory lesions. Acne washes containing salicylic acid 0.5-to-2 per cent may be helpful, however, most people will also need a topical retinoid, or retinoid agent or a combination of agents. Information on the treatment of acne is available at: www.hse.ie/eng/services/list/2/gp/antibiotic-prescribing/conditions-and-treatments/skin-soft-tissue/acne-vulgaris/.¹⁶

Impetigo

Impetigo is a common infection of the superficial layers of the epidermis that is highly contagious and most commonly caused by gram-positive bacteria (Figure 10 A/B). It usually presents as erythematous plaques with a yellow crust and may be itchy or painful. The lesions are highly contagious and spread easily. Diagnosis is typically based on the symptoms and clinical manifestations alone. Treatment involves topical and/or oral antibiotics and symptomatic care.¹⁷ Information on the treatment of impetigo is available at: www.hse.ie/eng/services/list/2/gp/antibiotic-prescribing/conditions-and-treatments/skin-soft-tissue/impetigo/.¹⁸

Urticaria

Urticaria, also known as hives, is a skin reaction that causes itchy welts, and is classified as acute or chronic (Figure 11). Acute urticaria is more common in children, while chronic urticaria is more common in adults. Acute urticaria presents as red raised areas of skin, often at several sites. This frequently resolves over a few hours, while chronic urticaria may persist for weeks. Acute urticaria is associated with possible triggers such as certain foods, medication, or contact with chemicals or latex products, however, up to 40 per cent of chronic urticaria cases are thought to be autoimmune related, eg, systemic lupus erythematosus (SLE), rheumatoid arthritis.⁴ For some patients no treatment is required, however, if itching is troublesome a non-sedating antihistamine such as cetirizine, or loratadine for adults and children, or fexofenadine may be needed. For severe symptoms, a course of oral corticosteroids (prednisolone 40mg daily for up to seven days) as well as an antihistamine may be needed if the rash is persistent and lesions are tender.⁴

Hidradenitis suppurativa

Hidradenitis suppurativa (HS), also referred to as acne inversa, is a chronic, relapsing, inflammatory skin condition that typically occurs after puberty, with the average age of onset in the second or third decade of life (Figure 12). Patients with HS present with inflammation of hair follicles in the apocrine gland-bearing regions; armpits, genital area, groin, inframammary region, perianal region, and buttocks that initially manifests as painful nodules or boils and progresses to abscesses, sinus tracts, and scarring. The presentation of HS is distinct, although the condition is often not well-recognised in primary care. The most troublesome symptom of HS is chronic pain, which is reported by almost all patients. The pain associated with HS can be intense and is reported by patients as the most significant factor contributing to impaired quality-of-life. Early diagnosis is very important for patients with HS, to ensure the best possible course and prompt disease management. However, HS diagnosis generally occurs after an average seven-year delay, because the early stages are often mistaken for other conditions. Information on the treatment of HS is available at: www.hse.ie/eng/services/list/2/gp/antibiotic-prescribing/conditions-and-treatments/skin-soft-tissue/hidradenitis-suppurativa/.²⁰

Rosacea

Rosacea is a chronic inflammatory dermatosis mainly affecting the cheeks, nose, chin, and forehead (Figure 13). It is more common in women and people with lighter skin, but symptoms can be worse in men. It is not known what causes rosacea, but some triggers can make it worse, including alcohol, caffeine, spicy foods, exposure to sunlight, and aerobic exercise. There is currently no cure for rosacea, but treatment can help control the symptoms.^21,22

Symptoms often begin with episodes of flushing, where the skin turns red for a short period, but other symptoms can develop as the condition progresses, such as burning and stinging sensations; permanent redness; spots (papules and pustules); and small blood vessels in the skin becoming visible. Rosacea is a relapsing condition. Long-term treatment is usually necessary, although there may be periods when the symptoms improve and treatment can be stopped temporarily. For most people, treatment involves a combination of self-help measures and medication.²³ Topical medications are usually prescribed first. These include metronidazole cream or gel, azelaic acid cream or gel, and ivermectin cream. If symptoms are more severe, antibiotics may be required. Antibiotics often used to treat rosacea include tetracycline, oxytetracycline, doxycycline, and erythromycin. These medications are usually taken for four-to-six weeks, but longer courses may be necessary if the spots are persistent. Redness and telangiectasia can also sometimes be successfully improved with vascular laser or intense pulsed light (IPL) treatment. These treatments may also improve flushing.²²

Secondary and tertiary specialist dermatology care

Lengthy waiting lists for dermatology services exist nationally, and many patients with debilitating skin conditions are waiting for prolonged periods. Dermatology outpatient referral numbers have increased significantly over the past decade in Ireland. At the end of 2019 there were 44,147 people waiting for a HSE dermatology outpatient appointment. However, at the end of 2022 this figure had decreased to 39,979.²⁴

Approximately 50 per cent of referrals to dermatology are for skin cancer, rates of which are rising rapidly and expected to double between 2020-and-2040.¹ There are 11 HSE Dermatology Departments (hub) and 16 Peripheral Clinics (spoke) operating a hub and spoke model (excluding CHI).