It is considered a chronic disease of children with a peak incidence between 2 and 15 years of age. It primarily affects the skin, bone, and cartilage. The disease is spread by person-to-person contact or by indirect contact (eg, via eating utensils). Risk factors include broken skin, overcrowding, and poor hygienic conditions.
A primary lesion is rarely seen. The earliest lesions are generally seen on the mucosa. Other early manifestations include painful osteoperiostitis of the long bones, condylomata lata, lymphadenopathy, and angular stomatitis (split papules). These early changes resolve with or without scarring. After many years, some patients develop destructive gummatous lesions of the skin and bones.
A65 – Nonvenereal syphilis
240686008 – Bejel
Differential Diagnosis & Pitfalls
Early and mid:
- Yaws – Very difficult to differentiate.
- Scabies – Mite prep positive.
- Fungal infections – Potassium hydroxide (KOH) positive.
- Impetigo – Honey crusted and occasionally bullous.
- Lichen planus – Striated scale.
- Psoriasis – Thickened scale.
- Tungiasis – Live flea present in nodules.
- Cutaneous leishmaniasis – More inflammatory and crusted.
- Arthropod bite – Rapid onset and inflammatory.
- Sporotrichosis – Associated with trauma, develops a lymphangitic spread.
- Atypical mycobacterial infections
- Tick granuloma
- Cutaneous tuberculosis – Usually more suppurative.
- Lobomycosis – Slower growing, smooth keloidal nodules.
- Cryptococcosis – Sometimes umbilicated.
- Juvenile xanthogranuloma – Yellowish in appearance.