Nicolau–Balus syndrome

Overview

Nicolau–Balus syndrome, also known as lichen ruber moniliformis, is an extremely rare variant of lichen planus. This chronic dermatologic condition is characterized by the appearance of small, flat-topped, keratotic papules arranged in a linear or necklace-like pattern, often involving the neck, chest, and trunk. The disorder was first described by Nicolau and Balus in the mid-20th century and is considered by some experts to be a rare presentation or subset of lichen planus or related keratinization disorders.

Due to its rarity, the syndrome is not well understood, and fewer than a handful of confirmed cases have been reported in medical literature. While it may resemble other dermatoses, its distinct clinical appearance and chronic course can help differentiate it when recognized by experienced dermatologists.

Causes

The exact cause of Nicolau–Balus syndrome remains unknown. Like classic lichen planus, it is believed to be an autoimmune-mediated condition in which the body’s immune system targets skin or mucosal cells. It may involve a T-cell–mediated response against basal keratinocytes, though specific immunologic triggers have not been clearly identified.

There are no known genetic, infectious, or environmental factors definitively associated with the syndrome, though some hypothesize that a hereditary predisposition may exist due to familial clustering in some reported cases.

Symptoms

The hallmark of Nicolau–Balus syndrome is the presence of distinctive papular lesions on the skin. These features may persist for years and are generally asymptomatic or mildly pruritic.

Dermatologic Features

• Multiple small, flat-topped, hyperkeratotic papules

• Linear or "rosary bead"-like arrangement of papules, particularly along the neck, chest, or upper trunk

• Coalescence of lesions into bands or plaques in some areas

• Brownish or reddish discoloration of the lesions

• Occasional mild itching or discomfort

Other Features (Rare)

• Scalp or mucosal involvement is uncommon

• Nails and oral mucosa are typically spared

• No systemic symptoms or internal organ involvement

Diagnosis

Diagnosing Nicolau–Balus syndrome can be challenging due to its rarity and resemblance to other dermatoses. Clinical suspicion, lesion morphology, and histological findings are key to confirming the diagnosis.

Diagnostic Steps

• Clinical examination: Identification of moniliform (beaded) arrangement of keratotic papules

• Dermoscopic evaluation: May help distinguish from other lichenoid dermatoses

• Skin biopsy: Reveals features similar to lichen planus, including hyperkeratosis, band-like lymphocytic infiltrate, and basal cell degeneration

• Histopathology: Can confirm diagnosis by showing interface dermatitis and other lichenoid changes

Treatment

There is no standardized treatment for Nicolau–Balus syndrome due to its rarity. Management is generally symptomatic and based on therapies used for other lichenoid dermatoses. Treatment focuses on improving cosmetic appearance and relieving any associated itching.

Commonly Used Treatments

• Topical corticosteroids: First-line treatment to reduce inflammation and lesion thickness

• Topical retinoids (e.g., tretinoin): May help normalize keratinization and reduce hyperkeratosis

• Calcineurin inhibitors (e.g., tacrolimus): Useful in steroid-sparing regimens or when lesions occur in sensitive areas

Systemic Options (For Severe or Refractory Cases)

• Oral corticosteroids: Short-term use to reduce inflammation

• Oral retinoids (e.g., acitretin): May be considered in widespread or persistent cases

• Phototherapy: Narrowband UVB or PUVA therapy may benefit some patients

Supportive Care

• Moisturizers to reduce dryness and scaling

• Patient education on chronicity and treatment expectations

• Regular dermatological follow-up to monitor progression and treatment response

Prognosis

The long-term outlook for Nicolau–Balus syndrome is generally favorable, as it is a non-life-threatening condition. However, it can be cosmetically distressing and resistant to treatment in some cases. Lesions tend to persist chronically, though periods of partial remission may occur with appropriate therapy.

Since the condition does not typically involve systemic organs or lead to serious complications, life expectancy is unaffected. Early diagnosis and consistent dermatologic care can help manage symptoms and improve quality of life. Further research and case studies are needed to better understand the syndrome's etiology and optimal treatment strategies.