While itchy, simple insect bites do not cause the profound lichenification, pigmentary changes ("leopard skin"), and presence of subcutaneous nodules (onchocercomas) seen in chronic onchocerciasis.
Leprosy is distinguished by a definite loss of sensation in the affected skin patches, which is not a feature of onchocerciasis.
This is thickened skin from scratching, but onchocerciasis is a specific parasitic cause, diagnosed by finding microfilariae in a skin snip.
The "leopard skin" of onchocerciasis is a specific pattern of hypopigmentation with perifollicular hyperpigmented spots, a unique appearance.
While both are itchy parasitic infestations, scabies is characterized by burrows and nocturnal pruritus, and lacks the subcutaneous nodules and skin snip findings of onchocerciasis.
Scleroderma involves hardening and tightening of the skin, a different pathology than the lichenification and pigmentary changes of onchocerciasis.
