A male patient came to the hospital with complaints of progressive swelling of the upper limb. On examination, the limbs are more swollen proximally than distally as shown below and is non-pitting. The skin over the swelling is thickened. What is the next best step in the management of this patient?

The given clinical picture is suggestive of lymphatic filariasis (elephantiasis). The best next step would be to test the night blood for worms since the filarial species is nocturnally periodic (between 10 pm and 4 am) in India. Lymphatic filariasis is caused by Wuchereria bancrofti and Brugia malayi. Elephantiasis is a delayed sequel to repeated lymphangitis, obstruction and lymphedema. Repeated leakage of lymph into tissues first results in lymphedema, then to elephantiasis. Treatment: Diethylcarbamazine is the drug of choice. Other options: PCR is negative in chronic filariasis. Lymphoscintigraphy is principally a research tool. X-ray is useful only if worms are calcified. Reference: Paniker&;s Textbook of Medical Parasitology 8th edition