6f Skin problems in palliative care

A man’s illness is his private territory and, no matter how much he loves you and how close you are, you stay an outsider. You are healthy.

Lauren Bacall, By Myself, 1978

Skin infiltration with subsequent ulceration or fungating wounds can be distressing. A small metastatic skin nodule is a visual reminder of disease progression and a fungating carcinoma with malodour, discharge and bleeding add to the misery of advanced and uncontrolled metastatic disease.

Loco-regional skin involvement (e.g. breast fungation) should be distinguished from generalized skin metastases which imply very late disease. Local extension of malignant tumour leads to embolization of blood and lymphatic vessels, compromising tissue viability. Infarction of the tumour leads to necrosis with subsequent infection, particularly anaerobic.

The ideal aim is complete healing through either local or systemic treatment, which may involve surgery, radiotherapy, hormonal manipulation or chemotherapy. If such treatment is inappropriate, then care is directed to the minimization of:

Treatment should be realistic and acceptable to the patient and carers. The primary aim is the promotion of comfort (as opposed to healing) and the enhancement of quality of life, which may hitherto have been severely impaired.

Following assessment of the problems, choose a dressing regime to meet the needs of the patient. Be prepared to change and experiment since there are no rights or wrongs. The aim is to contain problems and improve quality of life.

There are numerous commercially available products: hydrocolloids, hydrogels, alginates, semi-permeable films, cavity foams, desloughing agents and charcoals. All may have a place in the management of chronic wounds. The health professional must keep abreast of the merits of established and newer products. The simplest products may be the best and the most cost-effective.

The criteria are comfort, acceptability and availability.

Pruritus may be defined as ‘an unpleasant sensation that provokes the desire to scratch’. The prevalence is 27% with the common cancers and 80% in the presence of cholestasis.

This is complex and not fully elucidated, but it is known that both central and peripheral mechanisms are involved. A number of mediators including serotonin, neuropeptides, cytokines, prostaglandins and growth factors are being studied to generate future treatment options.

These can be divided into general causes of pruritus (which occur in the healthy population as well as those with cancer) and those specifically rela-ted to malignancy. In either case pruritus may be localized or generalized.

This is experienced by 50–70% of those over the age of 70 years. The majority have xerosis and skin atrophy, while in others the cause is unknown. It is best treated with general measures (see below) and the application of emollient cream.

The following drugs are common causes: opioids, aspirin, amphetamines and drugs that can cause cholestasis such as erythromycin, hormonal treatment and phenothiazines.

This can cause pruritus with or without anaemia, and responds to iron replacement.

Pruritus occurs in up to 11% of thyrotoxic patients, particularly long-term untreated Graves’ disease, and less commonly in hypothyroidism. The link between diabetes mellitus and pruritus is controversial.

Removal of causative agents (e.g. drugs) as well as the appropriate investigation and treatment of underlying disease are essential first-line measures. Management can be divided into general and cause-specific.

Evidence for the use of different systemic agents in the treatment of pruritus is limited, but specific drugs may be useful for specific situations as outlined below.

A 1–2% menthol solution in aqueous cream or oily calamine lotion with 0.5% phenol (which can be increased up to 1%) may be useful. Antihistamine creams should be used when the cause of itch is thought to be histamine-related, e.g. acute drug rash. Prolonged topical use, however, may lead to contact dermatitis, which is best treated with 1% hydrocortisone until it has settled.

Cancer per se is an infrequent, but important, cause of generalized pruritus (paraneoplastic itch), the mechanism for which is unknown. Pruritus is particularly associated with haematological malignancies such as Hodgkin’s lymphoma and polycythaemia rubra vera.

Treatment of an underlying lymphoma with steroids (dexamethasone 4–8mg o.d. or prednisolone 30–60mg o.d.) may be helpful. There is some evidence that paroxetine 5–20mg o.d. (see below), mirtazepine 7.5–15mg o.n. or cimetidine 800mg o.d. (or other H₂-receptor antagonists) may be effective (see below). Thalidomide may also be useful, but its association with teratogenicity and peripheral nerve damage may be difficult to manage.

Cimetidine, an H₂-receptor antagonist, has been shown to be helpful in itch associated with lymphoma and polycythaemia rubra vera. This is not thought to be a direct antihistaminic effect as it has little effect on itching caused by histamine, but is thought to be related to its inhibitory action on liver enzymes which are involved in the synthesis of endogenous opioids, and possibly other agents, causing pruritus.

Paroxetine, a selective serotonin-reuptake inhibitor (SSRI) antidepressant, has been shown to relieve itch in a case series of patients with advanced cancer with paraneoplastic and opioid-induced itch probably due to down regulation of 5 HT₃ receptors, but side-effects (nausea, vomiting and sedation) may limit its use.

Itch is a well recognized side-effect of opioids and a switch to another opioid (or stopping if possible) may be helpful.

Ondansetron has been shown to be useful in opioid-induced itch at traditional antiemetic doses, although most studies pertain to its success in treating the pruritus associated with opioids given by infusion into the epidural/spinal area. Opioid antagonists are theoretically useful in reducing pruritus but may reverse the essential analgesic effects.

In palliative care, cholestasis (causing itch) occurs most commonly due to obstruction of the common bile duct from primary or secondary tumours involving the pancreas and biliary tree. (It may also occur as a result of gallstones, drugs or intrahepatic disease.) Stenting of the common bile duct and relief of jaundice should relieve the itch, and dexamethasone may be of some help. Drug treatment may include an opioid antagonist (e.g. naltrexone 12.5–25mg o.d.) which may be helpful if the patient is not taking opioids for pain relief or an androgen (e.g. methyltestosterone 25mg sublingually o.d., or danazol 200mg o.d. t.d.s.). Alternatively, rifampicin 75mg o.d.–150mg b.d. may be used or colestyramine (but this is unpalatable and not effective in complete biliary obstruction) or charcoal which is equally unpalatable.

The pathogenesis of pruritus in renal failure has not been fully defined, but is thought to be multifactorial. Pruritus may be localized (in 70%) or generalized, and is more common in patients receiving dialysis than in those who are not. Ultraviolet light/phototherapy may be helpful. Opioid antagonists such as naltrexone may be effective but cannot be used in patients already receiving opioids because of the risk of reversing analgesia. Ondansetron, mirtazepine and thalidomide have been shown to be effective for generalized itch, whereas topical capsaicin cream can be effective for localized itch.

Lymphoedema is a collection of excessive interstitial fluid with a high protein content and is associated with chronic inflammation and fibrosis. It may occur in any part of the body, although generally in a limb. It is progressive and may become a grossly debilitating condition. Acute inflammation and trauma cause a rapid increase in swelling. In patients with cancer, lymphoedema is usually due to the blockage of lymphatic vessels and glands by malignancy or by fibrosis as a result of previous radiotherapy or surgery.

The aim of treatment is to prevent complications developing, and to achieve maximum improvement and long-term control. Success requires full patient cooperation and treatment strategies devised by a lymphoe-dema therapist (often a nurse or physiotherapist).

Treatment comprises two phases: intensive and maintenance. The inten-sive phase is indicated for those patients with moderate/severe lymphoedema and is therapist-led. It comprises daily treatment for a period of 2–4 weeks. Treatment includes manual lymphatic drainage, multilayer lymphoedema bandaging, skin care and exercise.

The maintenance phase focuses on self-management and includes simple lymphatic drainage, the use of compression hosiery, skin care and exercise.

Contraindications to compression include local extensive cutaneous metastases, truncal oedema (since fluid from a limb may be diverted to an already congested area), infection or venous thrombosis. Various drugs which influence capillary protein flux and filtration and reduce protein -viscosity in interstitial spaces are currently under evaluation but are not in regular use.

Chronic lymphoedema leads to changes in both subcutaneous tissue and skin which make them vulnerable to infection: