Acrokeratosis Paraneoplastica of Bazex
Bazex syndrome (acrokeratosis paraneoplastica of Bazex) is a rare paraneoplastic skin disorder, but one with serious diagnostic and prognostic significance. It causes red, scaly, psoriasis-like thickening of the skin (psoriasiform hyperkeratosis) that concentrates on the acral sites: fingers, toes, ear rims and the tip of the nose. In 80–90% of cases, Bazex syndrome is directly linked to squamous cell carcinoma (SCC) of the upper aerodigestive tract (nasopharynx, larynx, esophagus, oral cavity) or to lung cancer.
Importantly, the skin changes of Bazex syndrome often appear 2–12 months before the primary tumor is found. The mechanism is thought to involve the tumor releasing epithelial growth factors such as transforming growth factor alpha (TGF-alpha) and EGF, or an immune cross-reaction in which antibodies directed at the cancer also target structural antigens in the basement membrane and epidermis of the acral skin. The result is excessive keratinization (hyperkeratosis) and widespread superficial vascular inflammation.
Clinical Stages
The skin changes of Bazex syndrome evolve through three distinct stages that track the spread and invasion of the underlying tumor:
- Stage 1 (Acral Stage): Mild redness with violaceous or gray scale appears symmetrically on the ear rims, nose tip, fingertips and toes. Nail changes are prominent: subungual hyperkeratosis, onycholysis, longitudinal ridges and paronychia without infection.
- Stage 2 (Spread to Hands and Feet): Symmetrical hyperkeratotic plaques extend across the palms and soles, which crack and become painful with use, and scaly red patches appear scattered over the cheeks, chin, elbows and knees.
- Stage 3 (Generalized Stage): If the primary tumor is still undiagnosed and untreated, the psoriasis-like lesions spread to the trunk, legs, arms and scalp, producing a paraneoplastic generalized erythroderma.
Differential Diagnosis of Bazex Syndrome
| Bazex Syndrome (Acrokeratosis Paraneoplastica) | Acral Psoriasis | Dry Eczema / Hand Fungus (Tinea Manuum) |
|---|---|---|
| Paraneoplastic (SCC of the nasopharynx, larynx, esophagus, lung) | Chronic autoimmune disease with a genetic component | Allergic contact reaction or dermatophyte fungal infection |
| Ear rims, nose tip, fingertips and toes (symmetrical) | Hands, feet, elbows, knees, scalp | Hands and finger webs (often asymmetrical when fungal) |
| Paronychia, nail thickening and onycholysis appear very early | Oil-drop sign, nail pitting | Secondary nail deformity, no typical paronychia |
| No response or very poor improvement | Good response with rapid reduction of inflammation and scale | Good response to corticosteroids (eczema) or antifungals (fungus) |
| Serious prognosis that depends on finding the tumor | Chronic and relapsing, not directly fatal | Benign; clears once the cause is removed |
Diagnosis and Clinical Management at Haute-Derma
For patients with stubborn hyperkeratosis of the hands, feet and other acral sites, Haute-Derma follows a strict medical risk-management protocol:
Dermoscopy and Superficial Skin Imaging
- Digital dermoscopy: We look for adherent, dull gray scale, dotted or glomerular vessels on a red background, and complete loss of the fingerprint ridges (dermatoglyphics) on the fingertips.
- High-frequency skin ultrasound (HFUS, 22–50 MHz): Measures epidermal hyperplasia and inflammatory infiltration of the upper dermis, and confirms the absence of the destructive pattern seen in primary skin cancers.
Cosmetic Procedures Are Contraindicated
- No resurfacing procedures: CO2 laser, microdermabrasion and high-strength chemical peels must not be used on these keratotic lesions. Invasive treatment risks infection and fibrous scarring, and it delays the critical window for diagnosing a tumor of the upper aerodigestive tract.
Urgent Referral for ENT and Cancer Screening
When Bazex syndrome is suspected, the clinic starts a priority referral to specialist oncology or ear, nose and throat (ENT) hospitals:
- ENT and upper GI endoscopy: Flexible endoscopy carefully examines the nasopharynx, palate, larynx, hypopharynx and esophagus to detect squamous cell carcinoma (SCC) early.
- Chest and neck imaging: CT or PET-CT of the neck, chest and mediastinum to look for lung cancer or cervical lymph node metastases.
- Biopsy of suspicious lesions: Any abnormal mass in the upper airway is biopsied directly for a definitive histological diagnosis.
