People with dementia are confused by the loss of routine and are seeing their symptoms increase as a result of the Covid-19 outbreak, according to a charity.

Their health is deteriorating because of a lack of social contact, while carers are feeling isolated and struggling to get respite, the Alzheimer’s Society said.

Around 70% of people in care homes have dementia, while many others receive care in their own homes.

Care homes have had to close their doors to visitors during the crisis, while increasing numbers of care staff are unable to work because they are ill or self-isolating.

The charity has launched an emergency appeal for funds so it can continue to help people who may be isolated and without support to eat, wash and take medication.

The charity received nearly 3,300 calls about coronavirus during March – roughly 100 a day.

And its online community, Talking Point, saw a 600% increase in sign-ups over the last fortnight.

It anticipates a loss of around £20 million in fundraising income this year, and is furloughing 20% of its staff to ensure it can maintain frontline support.

Nice has always made clear that clinicians should take any decisions about care in conjunction with patients and their carers where possible, and it is particularly important that a holistic assessment is carried out in people with dementia

Kate Lee, the Alzheimer’s Society chief executive, said: “We are hearing daily from people with dementia worrying how to cope, confused, isolated and unable to get food deliveries, families struggling to explain what’s going on and carers unable to visit vulnerable people in person.”

The charity said it is also hearing from people with dementia who are “absolutely terrified” of going to hospital, where they are unsure they will receive the right treatment.

Guidelines released by the National Institute for Health and Care Excellence (Nice) state that healthcare professionals should assess patients with Covid-19 on the basis of “frailty”, before discussions around the provision of critical care.

The Alzheimer’s Society has asked for a review of the guidelines, and for them to make clear that “cognitive frailty is not discriminated against when having to make life or death decisions”.

Alzheimer’s Society dementia adviser Helen Payton said: “This week I have had lengthy phone calls offering people support and access to the information they need.

“Much of what I’m doing at the moment is emotional support – letting people talk and express their worries and frustration.

“Many are missing their family and worried about their care packages being reduced.

“One newly diagnosed person I spoke to cried when I told them I would phone them weekly to check in.

“They were so grateful to have someone there for them.”

A spokesman for Nice said: “With regard to Nice’s Covid-19 rapid guideline on critical care, this was developed to support critical care teams in their management of patients during this very difficult period of intense pressure.

“We are continually reviewing these guidelines in line with new evidence and as practice evolves to ensure that they are used as intended.

“Nice has always made clear that clinicians should take any decisions about care in conjunction with patients and their carers where possible, and it is particularly important that a holistic assessment is carried out in people with dementia.”