What is pseudoepitheliomatous keratotic and micaceous balanitis?
Pseudoepitheliomatous keratotic and micaceous balanitis (PKMB) is a rare skin condition that affects the penis. It is characterised by the presence of multiple small, scaly, and micaceous papules that gradually take on a silvery-white appearance.
Who gets pseudoepitheliomatous keratotic and micaceous balanitis?
PKMB is typically seen in older uncircumcised men, or those with predisposing risk factors (see causes).
What causes pseudoepitheliomatous keratotic and micaceous balanitis?
The cause of pseudoepitheliomatous keratotic and micaceous balanitis is not fully understood, but may be associated with chronic inflammation of the penile skin.
Contributory risk factors include autoimmune conditions, sexually transmitted infections, and poor hygiene. Individuals with a history of lichen sclerosus, genital warts, or human papillomavirus (HPV) infections may also be at increased risk.
What are the clinical features of pseudoepitheliomatous keratotic and micaceous balanitis?
PKMB appears as micaceous papules on the penis which may vary in colour from brown to grey and white, and can also appear silvery due to mica-like crusts and keratotic horny masses.
- These can vary in size from less than 1mm to several millimetres in diameter.
- They may be single or multiple, and distributed in a scattered or confluent pattern.
- The papules may ulcerate or bleed, and the affected skin may also be thickened or hyperpigmented.
Symptoms include an itching, burning, and painful sensation in the affected area as well as difficulty retracting the foreskin. Involvement around the perimeatal skin can cause difficulties with micturition.
What are the complications of pseudoepitheliomatous keratotic and micaceous balanitis?
Complications of PKMB can be due to chronic inflammation or ulceration. This includes:
- Secondary skin infections, such as bacterial and fungal
- Malignant transformation, such as squamous cell cancer
- Phimosis, scarring, and difficulties retracting the foreskin
- Sexual dysfunction, due to pain and discomfort
- Psychological impact, due to effect on quality of life and wellbeing.
How is pseudoepitheliomatous keratotic and micaceous balanitis diagnosed?
Skin biopsies of the affected area will help clarify the diagnosis of PKMB, as clinical appearances may mimic other conditions.
Histological findings typically show:
- Acanthosis — thickening of the epidermis
- Hyperkeratosis — thickening of the stratum corneum
- Pseudoepitheliomatous hyperplasia with no cytological atypia — an overgrowth of skin cells.
Histopathology may also show inflammation within the affected area, with infiltration of immune cells such as lymphocytes and plasma cells. For more information, see Pseudoepitheliomatous keratotic and micaceous balanitis pathology.
Additional investigations may help exclude other causes of the lesion including periodic acid-Schiff (PAS) stain for fungal infection, and genital swabs or serological testing for sexually transmitted infections.
What is the differential diagnosis for pseudoepitheliomatous keratotic and micaceous balanitis?
- Genital warts
- Bowenoid papulosis
- Balanitis xerotica obliterans
- Infections (eg, fungal skin infections, sexually transmitted infections)
- Malignancy (eg, squamous cell carcinoma)
- Inflammatory (eg, lichen sclerosus, psoriasis, Zoon balanitis)
What is the treatment for pseudoepitheliomatous keratotic and micaceous balanitis?
Treatment of PKMB can vary depending on the severity and extent of the condition.
- Maintain good personal hygiene.
- Reduce risk of sexually transmitted infections eg, using barrier protection.
- Topical steroids
- Immunosuppressants to control inflammation
- Cryotherapy, radiotherapy, surgical excision to remove areas of affected tissue
How do you prevent pseudoepitheliomatous keratotic and micaceous balanitis?
PKMB may be prevented by reducing irritation, inflammation, and infection of the genital area, by:
- Maintaining good personal hygiene practices
- Avoiding exposure to irritants such as chemicals and detergents
- Reducing risk of sexually transmitted infections by practicing safe sex and undergoing regular screening as appropriate.
What is the outcome for pseudoepitheliomatous keratotic and micaceous balanitis?
The outcome of PKMB can vary depending on the severity and extent of the condition. Some consider the condition premalignant, as malignant transformation to invasive disease has been reported.
Four stages of progression have been theorised by Krunic et al:
- Initial plaque stage
- Late tumour stage
- Verrucous carcinoma
- Transformation to squamous cell carcinoma and invasion.
Early diagnosis and treatment are essential for symptom control and reducing the risk of complications. The clinical course is chronic, and recurrences may occur following treatment.