Difference Between Paget’s Disease and Eczema

The key difference between Paget’s Disease and Eczema is that the Paget’s disease is a focal disorder of bone remodeling, and eczema is an inflammatory condition of the skin characterized by groups of vesicular lesions with a variable degree of exudates and scaling.

Paget’s disease occurs because of the mutations in certain genes such as nuclear factor kappa B, sequestosome p62, and osteoprotegerin. On the other hand, eczema occurs as a result of the hypersensitivity reactions mounted against different allergens. This difference in pathogenesis is the principal difference between the two diseases.

CONTENTS

1. Overview and Key Difference
2. What is Paget’s Disease
3. What is Eczema
4. Side by Side Comparison – Paget’s Disease vs Eczema in Tabular Form
5. Summary

What is Paget’s Disease?

Paget’s disease is a focal disorder of bone remodeling. Initially, there is an increase in the bone resorption which is followed by a compensatory increase in the new bone formation. The result is the formation of structurally abnormal bone tissue.

People above 40 years of age are the usual victims of this condition, and there is a female preponderance. A higher prevalence has been observed in the European region. The involvement of several genes including nuclear factor kappa B, sequestosome p62, and osteoprotegerin has been implicated in the pathogenesis of the Paget’s disease.

Clinical Features

• Bone pain (mainly in the spine or pelvis)
• Joint pain
• Bone deformities
• Neurological deficits because of the compression of cranial nerves mainly II, V, VII and VIII. Spinal stenosis and hydrocephalus can also happen.
• High output cardiac failure
• Pathological fractures
• Sometimes osteogenic sarcomas can also occur

Investigations

• X-ray – lytic lesions can be seen in the initial stage followed by a mixed phase and in the most advanced stage, abnormal bone formation can be identified.
• Isotope bone scan can be used to identify the extent of bone involvement
• Serum alkaline phosphatase level increases along with the urinary hydroxyproline level

Management

Bisphosphonates are the drug of choice in the management. The drug course is given intermittently depending on the serum alkaline phosphatase level and urinary hydroxyproline level. Asymptomatic patients with lesions identified in the radiological images if there is a potential risk of getting complications such as fractures of the weight-bearing long bones.

What is Eczema?

Eczema is an inflammatory condition of the skin characterized by groups of vesicular lesions with a variable degree of exudates and scaling. Vesicles form as a result of the edema in between the epidermal cells. There are different types of eczema. Atopic dermatitis is one of them. The other varieties of eczema include,

• Contact dermatitis

Contact dermatitis is dermatitis precipitated by exogenous agents, and often it is a chemical. Nickel sensitivity is the commonest contact allergy, affecting 10% of women and 1% of men.

Etiopathogenesis

Irritants than allergens mostly cause contact dermatitis. However, the clinical appearances of both seem to be similar. Allergic contact dermatitis is caused immunologically by type Ⅳ hypersensitivity reactions. The mechanism thorugh which irritants cause dermatitis varies, but the direct noxious effect on the skin’s barrier function is the most frequently observed mechanism.

The most important irritants associated with contact dermatitis are;

• Abrasives ex: frictional irritancy
• Water and other fluids
• Chemicals ex: acids and alkalis
• Solvents and detergents

The effect of most of these irritants is chronic, but a strong irritant causing necrosis of epidermal cells may produce a reaction within few hours. Dermatitis can be induced by repetitive and cumulative exposure to water abrasives and chemicals over several months or years. This commonly occurs in hands. Susceptibility of individuals with a history of atopic eczema to irritants, to have contact dermatitis is high.

Clinical Presentation

Dermatitis can affect any part of the body. When dermatitis appears at a particular site, that suggests a contact with a certain object. When a patient having a history of Nickel allergy presents with eczema on the wrist, it suggests an allergic response to a watch strap buckle. It is easy to list the possible causes by knowing the patient’s occupation, hobbies, past history and use of cosmetics or medicaments. Environmental sources of some common allergens are given below.

Through secondary ‘auto sensitization’ spread, allergic contact dermatitis can occasionally become generalized. The photo contact reaction is caused by the activation of a topically or systemically administered agent by ultraviolet radiation.

Management

The management of contact dermatitis is not always easy. This is due to many overlapping factors. The overriding objective is the identification of any offending allergen or irritant. Patch testing is useful in dermatitis of the face, hands, and feet since it helps to identify any allergens involved. The exclusion of an offending allergen from the environment is desirable to clear dermatitis.

But some allergens like Nickel or colophony are difficult to eliminate. Moreover, it is impossible to exclude irritants. Contact of irritants during certain occupations is inevitable. Protective clothing should be worn, adequate washing and drying facilities should be provided in order to minimize the contact with such irritants. Secondary to avoidance measures, patients can use topical steroids in contact dermatitis.

• Eczema herpeticum

Children with atopic dermatitis are at a higher risk of developing herpes viral infections. This may be life-threatening,

• Nummular eczema

Coin-shaped lesions appear on the trunk and the legs

• Paget’s disease of the breast

Eczema around the nipples and areola of women, which is most often due to an underlying carcinoma

• Lichen simplex

This is characterized by the formation of a localized area of lichens due to rubbing

• Neurodermatitis

Generalized itching and dryness of the skin

• Asteatotic dermatitis

Occurs in elderly people particularly on the legs

• Stasis eczema

These appear in areas of venous congestion

What is the Similarity Between Paget’s Disease and Eczema?

• Both are diseases of the musculoskeletal system

What is the Difference Between Paget’s Disease and Eczema?

Paget’s disease is a focal disorder of bone remodeling. Eczema is an inflammatory condition of the skin characterized by groups of vesicular lesions with a variable degree of exudates and scaling. Genetic mutations are believed to be the cause of Paget’s disease while Eczema is because of the hypersensitivity reactions.

Clinical Features

Clinical features of Paget’s include Bone pain (mainly in the spine or pelvis), Joint pain, Bone deformities, Neurological deficits because of the compression of cranial nerves mainly II, V, VII and VIII. Spinal stenosis and hydrocephalus can also happen, High output cardiac failure, Pathological fractures, and also sometimes osteogenic sarcomas can occur.

Eczema can affect any part of the body. When dermatitis appears at a particular site, that suggests a contact with a certain object. When a patient having a history of Nickel allergy presents with eczema on the wrist it suggests an allergic response to a watch strap buckle. Therefore, it is easy to list the possible causes by knowing the patient’s occupation, hobbies, past history and use of cosmetics or medicaments.

Investigation

With regard to paget’s disease; X-ray – lytic lesions can be seen in the initial stage followed by a mixed phase and in the most advanced stage, abnormal bone formation can be identified,  Isotope bone scan can be used to identify the extent of bone involvement, and  Serum alkaline phosphatase level increases along with the urinary hydroxyproline level. For Eczema, Skin prick test can be used for the identification of the potential allergens.

Treatment and Management

For paget’s disease, Bisphosphonates are the drug of choice in the management. The drug course is given intermittently depending on the serum alkaline phosphatase level and urinary hydroxyproline level. And the management of eczema is not always easy due to many and often overlapping factors which can be involved in any one case. Patch testing is particularly useful in dermatitis of the face, hands, and feet. It helps in identifying any allergens involved.  Moreover, the exclusion of an offending allergen from the environment is desirable in clearing dermatitis.

Summary – Paget’s Disease vs Eczema

Paget’s disease is a focal disorder of bone remodeling whereas eczema is an inflammatory condition of the skin characterized by groups of vesicular lesions with a variable degree of exudates and scaling. Mutations in certain genes are the cause of the Paget’s disease. Eczema, on the other hand, occurs because of hypersensitivity reactions mounted against various allergens. This is the main difference between Paget’s Disease and Eczema.

Reference:

1. Parveen Kumar. Kumar and Clark’s Clinical Medicine. Edited by Michael L Clark, 8th ed.

Image Courtesy:

1.’Paget’s disease in vertebra on CT’By James Heilman (CC BY-SA 4.0) via Commons Wikimedia  
2.’4149275665′ by Marek Isalski (CC BY-SA 2.0) via Flickr