Pruritus in the Elderly

• Pruritus in elderly is a Diagnostic and therapeutic challenge.
• Need to distinguish between
  • primary dermatological condition and
  • systemic disease manifestation.
• Presence of rash suggests primary dermatosis

Skin Changes in the Elderly:

• Two categories: intrinsic ageing (natural aging process) and extrinsic ageing (due to external factors).
• Combined effects of aging and external factors increase susceptibility to pruritic dermatoses.

Factors in Skin Ageing:

• Intrinsic: Reduced skin cell turnover, impaired barrier function, immune response, subcutaneous fat, thermoregulation, vascularity, gland activity, sensory perception.
• Extrinsic: UV exposure, pollution, smoking, lifestyle factors

Differential Diagnosis:

• Pruritus as a symptom of dermatological conditions or systemic diseases.
• Dermatological causes include xerosis, atopic dermatitis, contact dermatitis, dermatophytes, lice, psoriasis, scabies, urticaria.
• Systemic causes include neoplastic diseases, renal failure, liver disease, medications, haematological and endocrine disorders, tropical diseases, psychiatric and neurological disorders, infections like HIV.

Common dermatological causes of pruritus

Xerosis	This is the most common cause of pruritus in the absence of an identifiable skin lesion. It is characterised by dry, scaly skin, usually in the lower extremities.
Atopic dermatitis	Atopic dermatitis is characterised by pruritus and is defined as a chronic inflammatory skin disease commonly associated with allergic rhinitis or asthma.
Contact dermatitis	Contact dermatitis is caused by direct skin exposure to a substance (eg. poison ivy). It can be intensely pruritic.
Dermatophytes	Dermatophyte infections can cause localised pruritus with a characteristic rash of peripheral scaling and central clearing.
Lice	The pruritus is caused by a delayed hypersensitivity reaction to the saliva of the louse. These can be difficult to visualise without the use of a magnification aid.
Psoriasis	Pruritus can be present in a large number of patients with psoriasis. It may be generalised in this context and not necessarily restricted to the areas of psoriatic plaques.
Scabies	This is caused by the deposition of mite eggs within the epidermal layer of the skin. Symptoms of pruritus are often worsened at night.
Urticaria (hives)	This histamine-mediated condition is common and affects up to one quarter of the population. The lesions are well circumscribed, erythematous with an elevated wheal.

Common systemic causes of pruritus

Neoplastic/malignant diseases	Lymphomas (especially Hodgkin’s disease, seen in 30% of cases)Leukaemias (especially chronic lymphatic leukaemia)Any type of disseminated cancer and multiple myeloma
Renal impairment/failure	Chronic renal failure >50% of patients with chronic renal failure and 80% of patients on dialysis have pruritus
Liver disease/hepatic failure	Cholestasis from any cause including primary biliary cirrhosissclerosing cholangitisviral hepatitisdrug-induced cholestasis
Medications	DiureticsLipid-lowering agentsAngiotensin converting enzyme inhibitorsAnticonvulsantsAllopurinol
Haematological disorders	Polycythaemia veraIron-deficiency anaemiaMacroglobulinaemia
Endocrine disorders	HypothyroidismHyperthyroidismHyperparathyroidism
Tropical diseases	Various parasites
Psychiatric illness/disorders	Stress, anxietyDepressionPhobic disorders (eg. parasitophobia)Obsessive compulsive disorderHypochondriasis
Neurological disorders	Cerebral infarctBrain abscessMultiple sclerosisBrain tumours
Infection	HIV
Reproduced with permission from Dermatology Expert Group. Common causes of itch without rash (Table 4.15) [revised 2009 Feb]. In: eTG complete. Melbourne: Therapeutic Guidelines Limited; 2014 Mar.

Initial Patient Review:

• Comprehensive history and full physical/dermatological examination are crucial.
• Consideration of factors like resource limitations, cognitive impairment, depression, or physical disability in the elderly that may lead to neglect of hygiene.

History Assessment:

• Focus on onset, location, character, progression, and aggravating/alleviating factors of itch.
• Distinguish between acute (<6 weeks) and chronic (>6 weeks) pruritus.
• Identify if pruritus is associated with a rash or occurs without any visible skin changes.
• Assess the severity of itching, particularly if it disrupts sleep.
• Review recent changes in medications or dosages and use of over-the-counter products.
• Investigate the use of new cosmetics or creams.
• Explore history of atopy, eczema, asthma, or hay fever.
• Conduct a dietary history for potential nutritional deficiencies.
• Examine environmental conditions (like the use of electric blankets, heaters, hot showers).
• Check general health indicators (weight loss, appetite changes, mood, sleep patterns).
• Enquire about exposure to infectious diseases (rubella, mumps, varicella).

Physical Examination:

• Commonly observe xerosis (dry skin), especially in autumn and winter.
• Examine skin for excoriations, infections, lichenification due to chronic scratching.
• Check less visible areas like finger webs, intertriginous regions, and genital areas.
• Look for localised pruritus in dermatomal distribution or signs of neuropathic pruritus.
• Assess for psychogenic pruritus signs, such as scratching or picking at normal skin.

Secondary Causes Examination:

• Evaluate for organomegaly (liver, spleen enlargement) indicative of systemic disease.
• Palpate lymph nodes, especially in cases suspicious of lymphoma-related pruritus.

Investigations

1. Initial Tests:
   • Full blood count, renal function, liver function, fasting glucose, and thyroid function studies.
   • Blood count helps in assessing haematological disorders like leukaemias and anaemias.
   • Renal and liver tests for dysfunction; liver tests also for infections, hepatitis.
   • Age-appropriate cancer screenings due to neoplasm associations.
2. Skin Biopsy:
   • Generally not useful without visible skin disease.

Management

1. Lifestyle Modifications:
   • Short, cool showers under 3 minutes.
   • Use soap-free substitutes.
   • Patting the skin dry gently; avoid vigorous rubbing.
   • Applying emollients on damp skin post-shower.
   • Avoid excessive heating in winter.
   • Using a humidifier to maintain indoor humidity around 40%.
   • Avoid electric blankets.
   • Minimize contact with wool and synthetic garments.
   • Keep fingernails short to prevent scratching-related complications.
2. Medication Review:
   • Assess recent changes in medications that might cause pruritus.
   • Rationalize medications if necessary.
3. Stepwise Treatment Approach:
   • Emollients as the mainstay for maintaining skin hydration and breaking the itch-scratch cycle.
   • Trial of antihistamines, especially for urticarial symptoms.
   • Topical treatments like menthol 1% in aqueous cream.
   • Topical corticosteroids for underlying inflammatory or immunological conditions.
   • Phototherapy as an option for some patients.
   • Referral to a specialist if these measures are ineffective.

Key Points

• Pruritus in the elderly is often due to multiple factors.
• Prompt identification of causative factors is essential for effective management.
• Early management includes lifestyle changes, skin hydration, and topical treatments.