Alzheimer's disease is a chronic
neurodegenerative disorder resulting in part from the degeneration of cholinergic neurons in the brain.
Rivastigmine, a
cholinesterase inhibitor, is commonly used as a treatment for
dementia due to its ability to moderate
cholinergic neurotransmission; however, treatment with oral
rivastigmine can lead to gastrointestinal adverse effects such as
nausea and
vomiting.
Transdermal administration of
rivastigmine can minimize these adverse effects by providing continuous delivery of the medication, while maintaining the effectiveness of the oral treatment. While the transdermal form of
rivastigmine has been found to have fewer systemic adverse effects compared with the oral form, cutaneous reactions, such as
contact dermatitis, can lead to discontinuation of the
drug in its transdermal form. Lack of patient compliance with regard to applying the patch to the designated site, applying the patch for the correct length of time or rotating patch application sites increases the risk of cutaneous adverse reactions. This article outlines the diagnosis and management of
irritant contact dermatitis and
allergic contact dermatitis secondary to transdermal
rivastigmine. The large majority of reactions to transdermal patches are of an
irritant type, which can be diagnosed clinically by the presence of a pruritic, erythematous, eczematous plaque strictly confined to the borders of the patch. In contrast, an
allergic reaction can be differentiated by the presence of vesicles and/or oedema,
erythema beyond the boundaries of the
transdermal patch and lack of improvement of the lesion 48 hours after removal of the offending treatment. By encouraging the patient to follow a regular rotation schedule for the patch, and using
lipid-based
emollients for
irritant dermatitis and pre- and post-treatment topical
corticosteroids for allergic
dermatitis, cutaneous reactions can often be alleviated and patients can continue with their medication regimen. Other simple changes to a patient's treatment routine, including minimizing the use of harsh
soaps, avoiding recently shaven or damaged areas of skin and carefully removing the patch after use, can help to further decrease the risk of
dermatitis development.