Case-based learning: shingles
This article outlines how to recognise the signs and symptoms of shingles — a painful, blister-filled rash caused by the reactivation of the varicella-zoster virus — its causes and risk factors, and the role of pharmacists in managing treatment and preventing spread.
Shingles — also known as herpes zoster — is a painful, blister-filled rash caused by the reactivation of the varicella-zoster virus (VZV); the same virus that causes the primary infection varicella (i.e. chickenpox).
In the UK, the annual incidence is estimated to be around 1.85 to 3.9 cases per 1,000 people; this rises to 11 cases per 1,000 people in individuals aged over 80 years,. Individuals have a 20–30% risk of developing shingles during their lifetime. Shingles can affect people of any age, but the risk, incidence and severity increase with age. This is because the immune system becomes less effective with age, so ageing therefore increases the risk of developing shingles.
This article outlines how to recognise the signs and symptoms of shingles, its causes and risk factors, and the role of pharmacists in managing treatment and preventing spread to vulnerable patients.
Shingles is caused by a secondary viral infection (i.e. a second infection from a previous viral infection) of an individual nerve and the skin surface that is served by that nerve; this is referred to as a dermatome. The VZV lies dormant in the dorsal root ganglia, reactivating when the immune system is weakened, leading to herpes zoster infection. Most people only have one lifetime incidence of shingles; however, risk factors can increase this incidence. Patients presenting with shingles will previously have had chickenpox, typically in childhood.
The VZV is transmitted by direct skin-to-skin contact with a person who is actively shedding virus. It is in this phase shingles is contagious; once the vesicles crust over, the patient is no longer infectious. Although the virus can be spread, as shingles is a secondary infection it is not possible to catch it directly from another person. However, someone who has not had, or has been vaccinated against, chickenpox can contract that disease from contact with the fluid from open vesicles (i.e. burst blister) in active shingles.
The following groups have an increased risk of VZV reactivation and subsequent complications:
- Older people, particularly those aged 50 years and over, peaking in individuals aged over 80 years owing to reduced effectiveness of the immune system;
- People who are immunosuppressed from disease states (e.g. haematological malignancies, HIV) or taking immunosuppressive medications (e.g. for autoimmune conditions, chemotherapy, organ transplant);
- People with asthma and chronic obstructive pulmonary disease, thought to be owing to systemic inflammation and disruption of the immune system;
- Women — this is thought to be owing to lower threshold for consultation so they are therefore are more likely to seek help, leading to increased numbers reported in female patients, and to gender differences in response to reactivation of latent viral disease;
- People of non-Hispanic white heritage are at a two-fold risk compared with black ethnicities. This is thought to be owing to an underlying genetic factor that modifies the risk of VZV reactivation; however, further studies are needed to support this;
- People with a history of dermatological presentations, including eczema/dermatitis or trauma;
- Limited evidence suggests that people taking statins may have an increased risk, speculated to be because statins lower immunity;
- Psychological stress has been shown to increase incidence, owing to initiation of the stress response affecting immune response capacity to deal with the virus,,,,,,.
Symptoms typically include prodromal sensory phenomena (i.e. an early sensation) noted as tingling, prickling, burning and itching in a localised area along one or more dermatomes (an area of the skin supplied by nerves from a single spinal root) on the body. Other symptoms that may present, and can lead to incorrect diagnosis (see differential diagnosis below), include headaches, photophobia, malaise and fever.
Around 48 hours after onset of prodromal symptoms, the rash appears as an erythematous, maculopapular rash, with both flat, discoloured skin lesions (‘macules’) and raised bumps (‘papules’) of small fluid-filled blisters (see Figure) in a unilateral pattern from the body midline, correlating to the involved dermatomes. The most common areas involved are thoracic (58%) (see Figure 1A), cervical (20%) and ophthalmic (10–20%) locations (see Figure 1C).
The red aspect of the rash presents slightly differently on people with a darker pigmentation, decreasing the prominence of the red/pink background upon which the vesicles protrude.
The vesicles are initially clear, but eventually cloud, rupture, crust and involute. When the vesicles rupture they weep contagious fluid, increasing the transmission. In immunocompetent patients, the crusting occurs around day 7–10, with full resolution in 2–4 weeks. With patients that are immunocompromised, this can take longer and be more widespread, owing to the immune system’s reduced capacity to deal with the virus. Scarring and pigmentation can persist if deeper epidermal and dermal layers have been compromised by excoriation, secondary infection or other complications.
On rare occasions, the maculopapular rash might be absent — this is known as zoster sine herpete (ZSH).
Diagnosis of shingles is based primarily on the patient’s history. Asking questions to help confirm a diagnosis is essential, including:
- If the patient has previously had chickenpox;
- The symptoms experienced, including location, duration and severity.
This should be paired with physical examination that should reveal the characteristic location, distinctive fluid-filled blister rash, localised pain and prodromal phenomena.
Converse to this, in the absence of a rash, either before its formation or in rare, atypical cases — such as ZSH — physical examination may be inconclusive.
Confirming diagnosis via laboratory testing typically has no value; however, where diagnosis is unclear, laboratory testing or specialist advice should be sought. Samples obtained from a swab of an open vesicle, body fluid or skin scraping can be processed via polymer chain reaction to identify VZV DNA. Referral should be made for patients in high-risk categories and those with atypical presentations, particularly in immunocompromised patients or in those with severe complications, such as meningitis, encephalitis, myelitis or ophthalmic distribution.
Herpes simplex virus infections may be recurrent and may appear in a dermatomal distribution mimicking shingles, leading to misdiagnosis. Additionally, other common dermatological rashes may also be misdiagnosed, for example:
- Impetigo — more common in children and crusts yellow;
- Contact dermatitis — more common on the hands and face, where skin has come into contact with an irritant, causing it to become dry, cracked and irritated;
- Papular urticarial — allergic reaction on exposed areas, typically caused by bites;
- Candidal infection — lesion has a white discharge;
- Dermatitis herpetiformis — typically located on the backs of the elbows, the fronts of the knees, the scalp, bottom and back;
- Drug eruptions.
Complications can occur in all patients, but the prevalence and severity is higher in those who are immunocompromised. Some patients experience a persistent or recurrent pain in the involved distribution, known as post-herpetic neuralgia (PHN). This is the most common complication of shingles, and defined as pain persisting for more than 90 days after onset of rash, owing to nerve damage. It occurs in 10–13% of patients aged 60 years and over with the infection, and it is estimated that 14,000 cases of shingles result in PHN each year. PHN pain varies in severity and can be constant, intermittent or triggered by trivial stimuli (e.g. stress). PHN risk and severity is linked with older age, rash severity and the extent of trigeminal or ophthalmic rash, with PHN lasting for around three to six months, although on some occasions it can last for years.
Dermatological complications can also occur in all skin types, including scarring, pigmentation changes and secondary rash/keloid formation post-healing,. Secondary bacterial infections (typically staphylococcal or streptococcal) may also arise, resulting in cellulitis or life-threatening complications, such as necrotising fasciitis and sepsis.
Herpes zoster ophthalmic is characterised by V1 division of the ophthalmic nerve only, if left untreated. In severe cases, keratitis, corneal ulceration, optic neuritis, retinitis and blindness can occur,. Peripheral motor neuropathy may occur when a motor neurone is affected, resulting in movement disorders in the affected region, such as that seen in herpes zoster oticus (Ramsay Hunt syndrome), with associated acute peripheral facial nerve palsy, and vestibular and hearing problems.
Therapeutic choices depend on the severity of the patient’s symptoms, complications and risk factors. Generally, treatment provides the greatest benefit in people who are immunocompromised, those with prolonged or severe symptoms, and in those aged 50 years and over.
Conservative therapy is useful for patients with milder symptoms. This tends to include symptoms management, such as application of wet compresses for 30–60 minutes 4–6 times daily, and colloidal oatmeal baths, which can help with itching and irritation. Calamine lotion may also be used as an antipruritic, in addition to its mild antiseptic properties, to prevent infections caused by scratching the affected areas.
Antivirals work by preventing viral replication, thus stopping further vesicle formation. Antivirals are more effective the earlier they are started, shortening infection duration and decreasing the severity of PHN. Ideally, therapy should be initiated within 72 hours of symptom onset. However, antivirals have been shown to reduce pain even when started beyond the 72-hour window and should be considered for treatment of acute zoster infection regardless of the time of presentation.
Oral aciclovir, valaciclovir or famciclovir are antivirals that have all been shown to reduce viral shedding and the duration and pain severity associated with shingles. This works by targeting the viral DNA polymerase, inhibiting viral DNA replication and hence stopping viral replication. In severe or disseminated disease, intravenous therapy should be initiated. Topical antiviral therapy has not shown significant benefit and is therefore is not recommended.
Research has shown that valaciclovir and famciclovir may be superior to acyclovir in resolving pain and increasing skin healing time. Valaciclovir therapy accelerated the resolution of acute neuritis compared with acyclovir, reducing the median duration of pain by 13 days. In addition, the proportion of patients with pain persisting for six months was modestly lower in the combined valaciclovir arms versus the acyclovir arm. The reason for this is thought to be owing to higher plasma drug concentrations achievable with famciclovir and valacyclovir.
Valaciclovir and famciclovir have improved pharmacokinetics and bioavailability compared with acyclovir, so less frequent dosing is required, making them favourable for improved adherence. For immunocompetent patients, seven-day courses are sufficient, with longer courses needed in immunocompromised patients until two days after crusting of lesions. See table below for further information on the medicine used to treat active shingles.
|Table. Adult dosing for herpes zoster treatment|
|Dose (oral)||800mg five times per day||1,000mg three times per day|
500mg three times per day; alternatively750mg one to two times per day
|Common side effects||Photosensitivity skin reactions and pruritus, headache, dizziness, nausea, vomiting, diarrhoea, abdominal pains, fatigue, fever||Headaches are very common, alongside photosensitivity skin reactions and pruritus, abnormal liver function tests, nausea, vomiting, abdominal pain, diarrhoea, dizziness|
|Sources: Wood et al.; Electronic medicines compendium|
Pain can occur during and after a shingles infection and is the most debilitating symptom of the disease. Every effort should be made to reduce patients’ pain and suffering. Using a validated pain assessment scale, such as the visual analogue scale, allows subjective assessment to guide therapy.
Medications for pain relief include simple analgesia (e.g. paracetamol, non-steroidal anti-inflammatory drugs) and opioids (e.g. codeine, oxycodone). Tricyclic antidepressants (e.g. amitriptyline) and anticonvulsants (e.g. gabapentin, pregabalin) are effective for severe pain and PHN pains. The choice of analgesic therapy should be based on contraindications, drug interactions and adverse effects. Topical capsaicin or lidocaine are options for patients with localised, mild-to-moderate PHN pain, where systemic therapies are not feasible.
Corticosteroids have also been shown to be helpful in immunocompetent patients in the first 14 days following localised rash onset. They are often used in combination with aciclovir in uncomplicated acute herpes zoster presentations in an attempt to improve quality of life, healing of lesions and reducing PHN. Despite this, a meta-analysis of five placebo-controlled trials versus aciclovir did not demonstrate any benefit of combination therapy on quality of life or the incidence of PHN,. Owing to the potential adverse effects of corticosteroids reducing the immune response, these drugs should only be used in cases of severe pain with neurological involvement (e.g. facial paralysis), or central nervous system involvement. Corticosteroids should not be given without antiviral therapy.
Prevention is particularly desirable in older patients, owing to prevalence and complications. A single zoster vaccine (Zostavax, Merck Sharp & Dohme Limited) dose aims to prevent shingles development in older patients (see below) and can significantly reduce secondary complications, such as PHNs,.
The NHS shingles vaccination is available if you are aged 70–78 years, with a 2-year grace period, extending the vaccination to people aged 80 years who meet the criteria. Owing to the reduction in vaccination efficacy because of functional declines in the innate and adaptive immune system associated with ageing, patients aged 80 years and above, or 70 years and below, are not routinely vaccinated.
Zostavax is a live vaccine and should therefore be delayed in those that are acutely unwell and for 48 hours after the last dose of antiviral therapy. It is contraindicated in those on immunosuppressive or immunomodulatory therapies.
When to refer
Patients should be referred for specialist advice in the following cases:
- New vesicles forming after seven days of antiviral treatment, owing to increased suspicion of an underlying immunodeficiency syndrome;
- Recurrent shingles, as this is an atypical reactivation of shingles and may be a sign of underlying immunodeficiency;
- Pain inadequately controlled or when use of a strong opioid is considered. Neuropathic pain can be hard to control and often requires specialist input;
- Serious complications — such as meningitis, encephalitis or myelitis — are suspected;
- Ophthalmic shingle distribution of the trigeminal nerve, as detailed above;
- A severely immunocompromised person — related to medicine (e.g. corticosteroids or azathiopurine) or disease state (e.g. HIV) — or an immunocompromised person where the rash is severe, widespread or they are systemically unwell.
It would be important to check the patient’s accommodation status (e.g. do they live with vulnerable adults/children?), and their role (e.g. would active shingles be hazardous to others, for example in a nursing home?).
Shingle-specific counselling points
In addition to recognising and understanding the treatment for shingles, pharmacists should provide the following advice to patients:
- Avoid contact with people who have not had chickenpox, especially those who are at heightened risk of complications or transmission (e.g. pregnant women, immunocompromised people and neonates);
- Wear loose-fitting clothes to reduce irritation;
- Cover lesions that are not under clothes while the rash is still weeping with virus-dense contagious fluid. Covering the rash will help avoid accidental touching or scratching;
- Avoid the use of topical creams and adhesive dressings, as they can cause irritation and delay rash healing;
- Keep the rash clean and dry to reduce the risk of bacterial infection. Medical advice should be sought if there is an increase in temperature, as this may indicate bacterial infection;
- Avoid sharing clothes and towels, and wash these at a high temperature after use;
- Avoid direct sunlight if taking acyclovir or valaciclovir, and consider long-sleeved clothing and sun cream;
- Avoid work, school or nursery if the rash is weeping and cannot be covered (i.e. if it is located on the face). If the lesions have dried or the rash is adequately covered (i.e. with gauze bandage or clothing), avoidance of these activities is not necessary if the patient feels systemically well. If the patient works in a healthcare setting, advise that they must consult their occupational health department for advice on returning to work.
The following case studies help provide examples of how to approach patients with shingles in practice. The SOCRATES mnemonic provides specific questions that relate to pain and can be used to help ensure that the most is gained from consultations:
- Site — “Where exactly is the rash/pain?”
- Onset — “When did it start; was it constant/intermittent, gradual/sudden?”
- Character — “What is the pain like (e.g. sharp, burning, prickly)?”
- Radiation — “Does it radiate/move anywhere?”
- Associations — “Is there anything else associated with the pain/rash?”
- Time course — “Does it follow any time pattern, and how long ago did it present?”
- Exacerbating/relieving factors — “Does anything make it better or worse?”
- Severity — “How severe is the pain? Consider using the 1–10 scale.”
Case 1: Immunocompromised patient referred to A&E
A 39-year-old male*, Rafael, presents at his local accident and emergency department with a 4-day history of a rash over the right side of his groin, starting as erythematous and burning. He now has multiple red vesicular blisters, extending around the hips, groin and lower back. The patient describes the pain as extreme and, using a visual analogue scale, states it as 8/10 and says it feels like burning.
The patient’s history shows that he had chickenpox as a child and has had multiple sclerosis for three years. He takes mycophenolate 500mg twice daily for his multiple sclerosis, and has been taking paracetamol and dihydrocodeine for pain relief.
Based on the patient's symptoms, pattern of onset and medical history, a clinical diagnosis of shingles is made.
Advice and recommendations
As the patient is on immunosuppressant therapy and the rash is extensive, it is best to confirm the diagnosis by swabbing the open lesions for varicella-zoster virus. This is sent to the virology laboratory for confirmation of varicella-zoster DNA.
However, in the absence of a definite diagnosis, antiviral therapy should be started in this patient. As the patient is presenting >72 hours post-onset, valciclovir three times daily should be started; this should be reviewed and continued for two days after the rash has crusted. Owing to interaction with mycophenolate and the potential for haematological toxicity, consultation and referral for haematological advice should be sought.
Because of the patient presenting with severe pain and dihydrocodeine providing inadequate relief, it would be appropriate to step up to Oramorph 5mg four times daily, given on an as-required basis. Movicol liquid should also be recommended, at a dose of 25ml twice daily, to help with the constipation induced by morphine.
It is necessary to explain to the patient that he will be contagious until the vesicles crust over and to avoid contact with anyone who is immunocompromised or pregnant. The patient should be advised to contact his GP if his pain is not controlled.
Case 2: A patient experiencing shingles complications
A 75-year-old male*, Samuel, presents to his local pharmacy and asks to speak to the pharmacist in private.
When asked about the nature of his visit, Samuel says that he has persistent pain along the right hand side of chest. After asking about the chronology of Samuel’s symptoms and ruling out cardiac red flags or trauma, the pharmacist asks how long this has been occurring. Samuel said it has been five days.
In addition, the pharmacist checks the patient’s medical record and discovers that he was treated with acyclovir for shingles several weeks ago.
Owing to the patient’s symptoms and recent history of shingles, the pharmacists suspects post-herpetic neuralgia (PHN).
Advice and recommendations
The pharmacist explains that this is a common effect in those aged over 60 years and is a result of viral damage to the nerve fibres. The pharmacist states that PHN can last for a prolonged period (e.g. 12–24 weeks), and reassures the gentleman that it is self-limiting and manageable with analgesic medicine. The pharmacist offers simple analgesia, including paracetamol and ibuprofen, after confirmation that there are no cautions or contraindications for use. Calamine lotion and the regular application of cold compresses should also be advised to help combat the pain and soothe the area.
Owing to this gentlemen’s age and recurrent risk, the pharmacist signposts him to his local GP for vaccination against shingles and advises him to see his GP if the above interventions do not help. The pharmacist should also explain to the patient that there are other medicines available on prescription that may help with managing the pain (such as capsaicin cream, antiepileptics or antidepressants).
Finally, lifestyle advice is offered to help reduce the pain and discomfort, such as wearing loose-fitting clothes to lessen irritation.
Case 3: A carer seeking advice on working with active shingles
A 32-year-old nursery worker*, Saanvi, presents to the pharmacy and asks to speak to the pharmacist. The pharmacist offers Saanvi the privacy of the consultation room to discuss the issue, and she agrees.
When the pharmacist asks what brought Saanvi to the pharmacy today the patient explains that she has had a rash on one side of her torso for five days. She then proceeds to pull up her top to reveal dozens of small fluid-filled blisters across the left side of her trunk. The skin surrounding these blisters appears reddened. When asked how it feels, she describes a prickling and burning sensation on her skin around the site of the blisters.
The pharmacists suspects that it may be shingles, but wants to rule out other conditions by ascertaining a clinical, social and drug history.
The pharmacist diagnoses shingles and explains that the patient needs an appointment with her GP so a prescription for treatment can be produced. The patient has heard that shingles is very contagious and asks for advice around her work and how to avoid infecting others, including staff, children and parents.
Advice and recommendations
The pharmacist highlights that only those that have not had chickenpox, or the vaccine, can catch chickenpox from a patient with shingles with open vesicles (i.e. weeping blisters). Being a nursery worker, the patient will need to adopt extra precautions around pregnant women who have never had chickenpox, or been vaccinated, who are at risk of contracting chickenpox. In pregnant women, chickenpox has been shown to cause rare complications to both the mother and the foetus. Therefore, she should avoid work if the rash is weeping (contagious phase) and cannot be covered, but consult the human resources department to confirm the local policy. As the patient is displaying active shingles, the pharmacist counsels the patient on good hand and area hygiene to prevent spread, along with secondary infections and wearing loose-fitting clothing to reduce irritation. The pharmacist also offers paracetamol and calamine lotion for the pain and discomfort.
* All cases are fictional
- The British Association of Dermatologists has a patient information leaflet on shingles (herpes zoster): https://www.bad.org.uk/for-the-public/patient-information-leaflets/shingles
- The NHS website has patient information on shingles: https://www.nhs.uk/conditions/shingles/
- The Shingles Support Society has information on shingles and postherpetic neuralgia: https://herpes.org.uk/shingles-support-society/
About the author
George Bond is a senior patient service pharmacist at University College London Hospitals and Preet Panesar is a lead antimicrobial pharmacist at University College London Hospitals.
Citation: The Pharmaceutical Journal DOI: 10.1211/PJ.2021.20208674
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