Dermatology is a vast topic that junior doctors often find daunting. Do read our article on describing skin lesions. Fortunately, there are only a handful of conditions that are important to know as a junior doctor on the wards. These will be covered below:
Dermatitis is a generalised term describing irritation of the skin resulting in itching, dryness, and erythema. It can be caused by a specific irritant such as nickel, creams or generally be caused by stress or conditions such as eczema.
Patients will usually complain of itching of the skin which can occur at the flexural creases. The skin will appear erythematous, dry and itchy and lesions are usually poorly demarcated. Some patients may have very specific localised areas of dermatitis which may indicate that there is a specific irritant such as metal from clothing.
Usually, dermatitis can be managed well with emollients and ensuring the skin is always well moisturised. In more severe cases a short course of hydrocortisone cream can be given for one week alongside regular emollients. If a specific irritant is found, then that should be removed. For more on emollients & steroid cream, refer to the bottom of the article for guidance on creams & steroids.
Thrush is a fungal infection which can occur anywhere, but it is commonly seen on mucus membranes i.e. mouth, genitalia or creases of the skin i.e. in between the toes and groin creases.
Patients usually complain of itching and soreness around the affected areas. On examination, you may note lesions with white plaques at the affected areas and surrounding erythema.
A short course of topical antifungal can be used for cases of thrush. Always consult your local antimicrobial guidelines. If the thrush is recurrent or persistent then it is worth taking swabs and investigating for any underlying conditions that may be causing this such as diabetes or immunosuppressive conditions. This can initially be done with a set of blood tests.
Urticaria, also known as hives or wheals, are rashes that occur in the skin secondary to histamine release. The histamine release causes swelling within the superficial area of the skin resulting in a raised, red, often itchy rash. These can occur acutely or chronically. Generally, acute urticaria tends to occur in the context of an allergic reaction.
Patients with urticaria will often initially complain of itchiness, subsequently, they can have urticarial rashes that appear erythematous, with some mild swelling. They may also have associated swelling in other areas of the body due to urticaria in the deeper tissues, known as angioedema.
Always ensure to take an A to E approach so that the patient is stable; as urticaria can be associated with allergic reactions and angioedema. It is vital to ensure that the patient does not have airway compromise or an impending anaphylactic type reaction. Once this has been done, urticaria usually responds well to antihistamines which can be given regularly. In mild cases, you may choose to adopt a ‘watch and wait’ approach, as mild urticaria is generally harmless. Finally ensure you identify and rule out any triggers such as medication, foods, topical irritants. Remove and document these as appropriate.
Ulcers are a broad term for a breach in the skin which can be of varying depths. Generally, ulcers can be categorised as arterial, venous or diabetic, but there are other subtypes.
Ulcers are generally found on pressure areas such as the sacrum, heels and feet. Usually, due to the various co-morbidities that exist with ulcers, many patients may not realise that they are present and may be reported to you by nursing staff. Ulcers can vary in size and depth but are usually relatively well-demarcated. As patients may not be aware of them, they can often present in more severe cases.
Examine the patient properly and ensure that you expose the patient fully to look for other ulcers, particularly at the sacrum, where pressure sores can often be missed. If the ulcer looks infected ensure you take a swab for culture and consider starting the patient on some antibiotics. Ensure that once the ulcer is identified it is cleaned, dressed and examined regularly. Ensure that the patient’s comorbidities are well controlled, i.e. ensure the patient’s diabetes and other vascular risk factors are being treated adequately. With some more severe ulcers, it may be appropriate to refer these patients for review by the vascular or diabetic team as appropriate.
Cellulitis is an infection of the skin and soft tissues. It is commonly seen in patients in the lower extremities but can occur anywhere, particularly in cannula or line sites.
Cellulitis usually appears as a well-demarcated area of redness on the skin. Patients generally complain of warmth and tenderness at the site. The skin is flat and usually of normal texture but can appear dry and flaky. There may be a source of infection at the area affected such as an ulcer, cannula or arterial line, but it can occur without this. In severe cases, patients may be febrile, tachycardia and show other signs of septic shock.
As a junior doctor, managing cellulitis on the wards is generally straightforward. Firstly, mark the edges of the area with a marker or pen, to see if the cellulitis is worsening, spreading or regressing which helps to monitor its progress. If you suspect cellulitis, then you can start a patient on oral antibiotics as per your local trust’s guidelines which can be found on your hospital’s intranet, on microguide or through discussing with your hospital’s microbiologist. Usually, this is flucloxacillin 1g QDS or if it is more severe IV flucloxacillin for 5-7 days.
If there are any areas which are leaking or are exuding pus, then it is vital to take a swab to ensure that the correct antibiotics are being administered. Finally ensure to review the patient regularly particularly looking to see if the cellulitis is spreading beyond the marked site, as this may prompt the consideration of more aggressive treatment or considering an alternative diagnosis.
Vasculitis comprises a range of conditions which cause inflammation of the blood vessels and a variety of sequelae as a result of this. There are a broad set of subtypes which we will not cover in-depth here as it is unnecessary to know it in detail at this stage. Instead, we will briefly be covering the initial investigations and managements that are important to carry out if vasculitis is suspected.
From a dermatological point of view, vasculitis presents as a classical purpuric rash which can range in size. A purpuric rash is one where there is bleeding subcutaneously giving the appearance of a red/dark purple rash on the skin. A vasculitic rash will blanch. A purpuric non-blanching rash could be meningococcal meningitis which needs prompt senior escalation.
Vasculitic rashes are typically non-itchy and do not change the texture of the skin. As patients with vasculitis may present with sequelae as a result of impaired blood flow to other organs. It is important to enquire about & investigate for issues with other major organ systems. Make sure to ask patients whether they have noticed haematuria, frothy urine, chest pain, abdominal pain, headaches, visual changes or haemoptysis. Any of these symptoms could suggest a more severe or aggressive form of vasculitis, which requires senior escalation.
If you suspect a vasculitic rash first, ensure that the patient is stable by assessing the patient with an A to E approach. In extreme cases, some aggressive forms of vasculitis can cause hypoxia and fluid imbalances. Once you are confident that the patient is stable it is important to do some basic examinations and investigations to look for any end-organ damage which would determine the urgency of senior referral. Consider the steps below:
- Always start with an ABCDE approach and do a full set of observations.
- Ensure the patient has a patent airway and do a full respiratory examination specifically auscultating for crackles that may suggest pulmonary haemorrhage. Also, examine the nasal passage and throat as granulomatosis with polyangiitis can cause some breakdown and secretions at the nasal septum.
- Auscultate the chest to listen for any murmurs or signs of pericardial effusion. Check all peripheral pulses.
- Do a brief abdominal examination, palpating for any obvious tenderness.
- Expose the patient and look to see the extent and spread of the rash. Furthermore, observe at this stage for any obvious oedema which could suggest early stages of renal damage.
- Initial investigations should involve a urine dip for protein and blood. If either is positive send the sample off for a urine PCR. An ECG acts as a good baseline for comparison in the future. If there are any signs of chest involvement, then organise a chest x-ray.
- Safety net the patient and urge them to contact you or any other staff if any new symptoms appear or if their rash worsens.
- Finally, regardless of the extent of end-organ damage notify your senior regarding your findings. It is also important to get early advice and referral to the rheumatology team and any other appropriate teams such as renal and respiratory. They will usually recommend starting the patient on a course of steroids and may review the patient as an inpatient or outpatient.
Necrotising fasciitis is a rare but important diagnosis to be aware of as it is life-threatening. It is an infection of the deep tissues i.e. fascia, muscles, subcutaneous tissue and dermis. It causes the death of the infected tissue and therefore immediate treatment is vital.
The key presentation of this condition is pain and tenderness that is out of proportion to what is seen on physical examination. This condition can look similar to cellulitis with erythema and swelling. The key difference is that the margins will be poorly defined and there will be intense pain beyond the margin of the erythema. As necrotising fasciitis progresses you will notice signs of ischemia, such as poor pulses, discolouration, hard skin and subcutaneous emphysema. There may also be systemic signs of illness such as a fever, tachycardia, low blood pressure and other signs similar to that of a septic patient. Usually, necrotising fasciitis will be resistant to antibiotics and most analgesia.
There is one bedside test that can be used by your seniors if necrotising fasciitis is suspected, known as the ‘finger test’. This involves making a 2cm incision in the suspected area usually down to the fascia and inspecting for signs of ischemia such as poor blood flow and dishwater coloured pus. You can then insert a finger with sterile gloves down to the fascia; if there is minimal resistance as you go through the tissues then this increases the likelihood of necrotising fasciitis.
It is vital to identify and treat necrotising fasciitis quickly. If you suspect necrotising fasciitis, then escalate this to a senior immediately and to a general surgical or orthopaedic team depending on your local protocol. Necrotising fasciitis is definitively treated with surgical debridement so the patient will most likely need surgery. In the meantime, you can start the initial workup required for theatre such as blood gases, bloods, group and save, fluids and ECG. DO NOT let any of this delay taking the patient to theatre or making a referral.
Chronic venous insufficiency
Chronic venous insufficiency refers to a condition where there is poor venous return secondary to venous reflux. It typically affects the lower legs.
Patients tend to initially present with non-specific skin changes such as hyperpigmentation, venous ulcers, dermatitis (venous eczema), atrophie blanche – white plaques on the skin and chronic swelling. They make also complain of pain and itching of the skin.
Chronic venous lymphoedema is usually a clinical diagnosis based on history and classical examination signs. However, doppler ultrasounds can also be done in conjunction to help look at the flow through the vein.
Management involves using conservative methods to help support venous return such as manual compression stockings, leg elevation, rest and use of emollients for dermatitis. Some surgical options such as ablation therapy can be used in severe cases.
It is incredibly important to look for signs of DVT, phlebitis or superficial vein thrombosis in patients with chronic venous lymphoedema as these can co-exist and sometimes worsen the condition. If you suspect any of these, organise an ultrasound doppler of the affected leg and make sure to inform a senior.
Lymphoedema refers to the swelling of a specific part of the body due to improper lymphatic drainage. In practice, this tends to occur in the lower limbs. The cases seen in practice tend to occur secondary to chronic venous disease, surgery (lymph node removal), radiotherapy, trauma, infection or poor mobility.
Patients present with swollen extremities and may complain of a feeling of heaviness and tightness. They may report pain in the affected area. On examination, you will note that there is a reduced range in movement due to the swelling, changes in skin texture and temperature and altered sensation. Generally, lymphodema is pitting. Diagnosis is made clinically by ruling out any other differentials.
Firstly it is vital to rule out any serious conditions such as DVT, cellulitis or thrombophlebitis. Ensure you do a full set of bloods as part of the workup. If there is any suspicion of DVT then organise an ultrasound of the affected leg.
If all serious underlying causes are ruled out then the mainstay treatment is conservative similar to that of chronic venous lymphodema. Encourage elevation, compression stockings (if there are no contraindications), consider looking at any medications that may worsen this, also consider systemic conditions such as heart failure that can cause this. In the case of heart failure, a BNP test, ECG and echo would be appropriate initial investigations.
Cold sores/genital herpes (Herpes simplex virus)
The herpes simplex virus presents with painful blistering lesions and commonly affects the mouth (cold sores) or genital regions. It is transmitted by the touch of an active lesion, however asymptomatic viral shedding can also occur. After a primary infection, herpes can recur multiple times as the virus lies dormant in the nerve root.
Patients will present with shallow blistering lesions, which they will report as being intensely painful. Genital lesions can present with dysuria and sometimes urinary retention due to the pain. There may also be systemic symptoms such as fever or an associated systemic infection and lymph nodes.
Diagnosis is usually made clinically but viral swabs can be taken and sent off to confirm the diagnosis. There is no treatment for mild cases and regular analgesia along with warm salt baths can be advised. In very early cases topical acyclovir can be used to shorten the duration of an attack. Definitely escalate patients with widespread lesions or those near the eye.
In severe infections or in those who are immunocompromised, start the patient on acyclovir, valaciclovir or famciclovir based on your local guidelines & escalate to seniors. Infections tend to last for about 2 weeks.
There is a vast selection of emollients that can be used to prevent moisture loss in the skin. Broadly they are either water or oil-based. Oil-based emollients are generally better at moisturising, however, they are thicker and therefore water-based emollients are better tolerated. Below is a list of some common emollients, but please note that there is a vast range of different emollients that may not be listed below.
The general rule of thumb is to prescribe about 500g and to use the greasiest tolerated emollient possible. This helps ensure that the skin is rehydrated as much as possible. If steroid creams are used in conjunction with emollients it is important to use them at different times to prevent dilution of the steroid. Side effects of emollients are usually uncommon but can include irritation or allergic-type reactions.
- Light – Aveeno, E45 cream.
- Moderate – diprobase cream, double base cream.
- Greasy – Hydrous ointment (also known as oily cream)
- Very Greasy – 50:50 ointment white soft paraffin: liquid paraffin, epaderm cream.
Steroid creams are used to help reduce inflammation in skin conditions. It is generally suitable in dermatitis, eczema and psoriasis. Do not use it in skin infections such as fungal infections. Generally, a seven-day course of topical steroids 2-3 times a day to the affected area is effective. Below is a list of the basic steroid creams based on potency.
- Mild – 1% hydrocortisone – can be used on the face and body.
- Moderate – Eumovate (clobetasone butyrate), modrasone – can be used short term for the face and body.
- Potent – Betnovate (betamethasone valerate), Elocon – Avoid the use of this on the face where possible.
- Very potent – dermovate (clobetasol propionate) – Do not use this steroid cream on the face.
Buzzwords and pattern recognition
Certain skin lesions have pathognomic presentations that help to identify the nature of the lesion. The more common and useful ones, to help in identification and handover, are listed below.
- White plaque – fungal infection, psoriasis.
- Scales – psoriasis
- Satellite lesions – fungal infection.
- Groin creases/in between toes – fungal infection.
- Excoriations – eczema/dermatitis.
- Target lesions (concentric rings) – erythema multiforme.
- Annular lesions – common in ringworm.
- Purpura – prolonged pressure to an area e.g. with TED stockings, vasculitis.
- Depigmentation – vitiligo.
- Hypopigmented lesions – pityriasis versicolor i.e. fungal infection.
- Clustered vesicles in a dermatomal distribution – shingles.
- Golden crusted lesion – staphylococcus aureus infection.
- Striae – excessive steroid use or production.
- Tense, itchy blisters – bullous pemphigoid.
- Flaccid, rupturing blistering with erosions – pemphigus vulgaris (involves mucous membranes).
- Linear burrow – scabies (particularly in between fingers, feet, genitals).
All images are from DermNetNZ.org.
Written by Dr Thujina Thillainathan
Proofreading by Dr S Javadzadeh CT1
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