Palmoplantar Keratoderma - Causes and Treatment

What Is Palmoplantar Keratoderma?

Palmoplantar keratoderma (PPK) is a commonly encountered problem in day-to-day practice. This disease presents as distressing, thickened skin with a fissured pattern intermingled with recurrent eczema-like flare-ups. Keratoderma in certain rare syndromic forms may involve other organs besides the skin, serving as an indicator of underlying internal abnormalities. Treating all kinds of inherited and non-inherited keratodermas can be tough. Many treatments only make things better for a short time and can have side effects.

What Are the Different Types of Palmoplantar Keratoderma?

Skin problems can show up on the palms of the hands and the soles of the feet of people who are affected. There are different types of this condition, some are passed down through families and only affect the skin, some are part of larger inherited syndromes, and others are acquired later in life. Among these types, hereditary types are more commonly seen. These can either affect just the hands and feet or be part of a wider skin issue.

1. Focal Hereditary Palmoplantar Keratodermas - Focal keratodermas mainly affect pressure areas.

• Palmoplantar keratoderma striatam or areata type (autosomal dominant pattern).

• Hereditary painful callosities (autosomal dominant).

• Howel-Evans syndrome or tylosis (autosomal dominant).

• Richner-Hanhart syndrome (autosomal recessive).

• Pachyonychia congenital (autosomal dominant).

• Striate palmoplantar keratoderma accompanied by dilated cardiomyopathy and woolly hair (autosomal recessive).

2. Diffuse Hereditary Palmoplantar Keratodermas - Diffuse keratodermas affect most of the palms and soles.

• Unna- Thost type (autosomal dominant).

• Vorner's type (autosomal dominant).

• Mal de Meleda type (autosomal dominant or recessive).

• Huriez syndrome (autosomal dominant).

• Olmsted syndrome (unknown inheritance pattern).

• Vohwinkel syndrome (autosomal dominant).

• PPK with sensorineural deafness (mitochondrial inheritance).

• Bart-Pumphrey syndrome (autosomal dominant).

• Hidrotic ectodermal dysplasia (autosomal dominant).

• Papillon-Lefevre syndrome (autosomal recessive).

• Palmoplantar keratoderma Nagashima type (autosomal recessive).

• Diffuse palmoplantar keratoderma accompanied by arrhythmogenic cardiomyopathy and woolly hair (autosomal recessive).

3. Punctate Palmoplantar Keratodermas - Punctate-type keratoderma results in tiny bumps on the palms and soles and shows an autosomal dominant pattern.

• Punctate keratoderma.

• Filiform keratoderma.

• Marginal keratoderma (acrokeratoelastoidosis).

4. Acquired Palmoplantar Keratodermas - This type can either be focal or diffuse.

• They can develop alongside various skin and internal conditions.

• These include inflammatory skin conditions like eczema or psoriasis, infections, medications, toxins, internal cancers, systemic inflammatory diseases, circulation issues, and sun damage.

What Causes Palmoplantar Keratoderma?

The causes of palmoplantar keratoderma could be either.

1. Exogenous or external factors like irritants, allergens, infections, and more.

2. Endogenous factors or internal factors like atopic dermatitis, pompholyx, psoriasis, and others.

The reason behind hereditary keratodermas is a gene problem that makes the skin protein (keratin) abnormal. These conditions can be passed down from parents in two ways: either through an autosomal dominant pattern or an autosomal recessive pattern. Most often, the abnormal skin involves only the palms and soles (non-transgradient palmoplantar keratoderma), but sometimes it extends onto the top of the hands and feet as well (transgradient).

What Are the Clinical Features of Palmoplantar Keratoderma?

• The skin on the palms and soles becomes harder and thicker.

• Rough, scaly areas may appear, often in white, yellow, or brownish colors.

• Due to thickening, the skin may crack or split, especially in areas under pressure, causing discomfort.

• PPKs can cause pain and discomfort, particularly during activities like walking or using hands.

• Both hands and feet are usually affected similarly.

• Nails might also change, becoming thicker or developing ridges or pits.

• Palmoplantar keratodermas can start at various ages and may worsen over time.

How Is Palmoplantar Keratoderma Treated?

Primary treatment includes measures for correcting the underlying cause by using antipsoriatic agents and antifungal agents and avoiding irritants (like detergent, hard soap, or cleanser) or allergens.

Associated fungal or bacterial infections, dermatitis, and hyperhidrosis (excessive sweating of palms and soles) should be treated adequately. Symptomatic measures like antihistamines or painkillers may be required in painful fissures. Due to the thickening of the skin in this condition, topical medicines have limited effect. However, their absorption can be increased by using occlusive dressing. Scrubbers or pumice stones used during manicures and pedicures also serve a similar function. The use of properly fitted footwear and socks can prevent the fissuring of the sole by protecting it from environmental insults and providing occlusive effects.

• In mild cases (localized or diffuse keratoderma), moisturizer with a barrier cream can be used. Soak the affected part in sodium chloride for 10 to 15 minutes, and it will help soften the skin, which can be quickly scrubbed. Keratolytic agents like Dithranol, coal tar, Tretinoin, and Tazarotene are helpful.

• In moderate cases (extensive keratoderma with few superficial fissures), topical steroids like Mometasone and UVA (ultraviolet A) are useful.

• In severe cases (extensive keratoderma with multiple deep fissures that bleed), use topical high-potent steroids like Halometasone, Clobetasol, and others, and PUVA (phototherapy). Systemic steroids, retinoids, and cytotoxics like Methotrexate, Azathioprine, and Cyclosporin A must be considered.

All topical agents should preferably be in an ointment base and provide occlusion with the application of a polythene sheet over the applied cream; it helps in better active drug penetration and produces beneficial results. In the absence of cutaneous irritants or deep fissures, keratolytic agents should be used first, followed by other drugs, to yield better results. Since cumulative insult dermatitis or allergic contact dermatitis is common, simple measures like repeated application of cooking oil prove useful in maintaining beneficial effects by fastening the absorption of specific topical medicines.

Systemic medications like steroids (Prednisolone, Deflazacort), retinoids (Acitretin), and other medications are used only in severe cases because of their dependency and toxicity. As most of these conditions are recalcitrant, a combination treatment is most effective and should be gradually worked up, starting from the mildest to the drastic measures.

Conclusion:

Hereditary PPK happens when the skin grows too much because of changes in certain genes. It can show up in different ways, like spreading out evenly, in patches, lines, or tiny dots. Sometimes, it can spread over time. PPK might show up alone or along with other skin or body features. Treatment mostly focuses on easing the symptoms. Treating it needs to be personalized, and using antibacterial and antifungal treatments regularly can help. It can include things like soaking in saltwater, gently scraping away thickened skin, using special creams or medicines to soften the skin, or even having surgery to remove thickened skin and replace it with healthier skin from elsewhere on the body. Keeping the skin hydrated and taking care of it are also important parts of treatment.