What are the causes of a palmar rash?

From the Guidelines

Palmar rashes can be caused by various conditions, including psoriasis, which is a significant cause of morbidity and mortality due to its impact on quality of life, as seen in a case study where a 66-year-old man presented with a 15-year history of psoriasis involving the palms and soles, significantly impacting his quality of life 1.

Causes of Palmar Rash

The causes of palmar rash include:

• Contact dermatitis from exposure to irritants or allergens
• Eczema, particularly dyshidrotic eczema, which causes small, itchy blisters
• Psoriasis, presenting as well-defined red patches with silvery scales
• Fungal infections like tinea manuum
• Scabies from mite infestations
• Secondary syphilis, which can cause non-itchy copper-colored rashes
• Drug reactions to medications
• Systemic conditions like lupus or HIV
• Hand, foot, and mouth disease, commonly causing palmar rashes in children
• Allergic reactions to latex gloves or chemicals, frequent in healthcare workers and those with occupational exposures

Treatment and Management

Treatment depends on the underlying cause and may include:

• Topical corticosteroids like betamethasone 0.05% cream applied twice daily for 1-2 weeks for inflammatory conditions
• Antifungal creams like clotrimazole 1% for fungal infections applied twice daily for 2-4 weeks
• Antihistamines like cetirizine 10mg daily for allergic reactions
• Avoiding triggers and maintaining good hand hygiene without excessive washing is important for management
• If the rash persists beyond 2 weeks despite over-the-counter treatments, spreads rapidly, or is accompanied by systemic symptoms like fever, medical evaluation is necessary for proper diagnosis and treatment, as some conditions like erythrodermic psoriasis may require systemic treatments such as oral cyclosporine or acitretin 1. In cases of erythrodermic psoriasis, the treatment approach should prioritize short-term efficacy, and oral cyclosporine or acitretin may be considered due to their rapid onset of action, as seen in a study where acitretin was used to treat a patient with severe psoriasis, resulting in substantial improvement in both palmar and plantar psoriasis 1.

From the Research

Causes of Palmar Rash

• Secondary syphilis can cause a maculopapular rash on the palms of the hands and soles of the feet, as seen in a case study where a 40-year-old male presented with a diffuse body rash after a sexual encounter 2.
• Vesicular hand dermatitis, also known as pompholyx, dyshidrosis, or dyshidrotic eczema, can cause eruptive, symmetric, vesicular, and/or bullous dermatitis on the palms and/or palmar aspects or sides of the fingers 3.
• Contact dermatitis is a common inflammatory skin disease that can cause hand dermatitis, including palmar rash, due to exposure to contact allergens and irritants 4.
• Dyshidrotic eczema is a common cause of palmar dermatitis, characterized by a recurrent vesicular eruption affecting the soles, palms, or both, and is very pruriginous 5.
• Syphilis is a sexually transmitted disease that can cause a variety of mucocutaneous lesions, including a palmar rash, and its incidence has been increasing in the USA since 2000 6.

Types of Palmar Rash

• Maculopapular rash: a type of rash characterized by flat, red patches on the skin, often seen in secondary syphilis 2.
• Vesicular rash: a type of rash characterized by small, fluid-filled blisters, often seen in vesicular hand dermatitis and dyshidrotic eczema 3, 5.
• Eczematous rash: a type of rash characterized by inflammation and irritation of the skin, often seen in contact dermatitis and dyshidrotic eczema 4, 5.