The 62-year-old veteran war correspondent for La Stampa daily, who returned to Italy in the night between Sunday and Monday, wrote a first-person account of his captivity in the newspaper.
Quirico said he and Piccinin entered Syria on April 6th with members of the Free Syrian Army (FSA) and were captured near Qusayr not far from the Lebanese border.
He said they were probably betrayed by members of the FSA.
They were beaten by rebels belonging to a group called al-Faruk and taken to a house in Qusayr, the journalist said.
These rebels "take advantage of the Islamic veneer and the context of the revolution to take over vast tracts of territory, hold the population to ransom, kidnap people and fill their pockets," he said.
The journalist said he and Piccinin suffered a "terrible and extraordinary saga", being shifted around the country and making two escape attempts.
In June, following attacks by Hezbollah on Qusayr where they were being held, they were forced to leave the city for Homs along with thousands of civilians.
During this "exodus", Quirico said he borrowed a mobile phone from a wounded rebel soldier to call home.
"It was the only gesture of pity I received in 152 days of captivity," he said.
"Even children and old people tried to hurt us. Maybe I am putting this in overly ethical terms but in Syria I really found a country of evil," he said.
"We were treated like animals, locked in small rooms with shuttered windows despite the stifling heat, thrown on straw mattresses, fed with scraps," he added.
"In all my life, I never felt that kind of daily humiliation," he said.
He said their captors carried out two mock executions, including one in which a rebel put his head against a wall and held the barrel to his temple.
"During those interminable moments, I felt ashamed...It is your own fear that enrages you," he said.
"The West trusts them but I discovered at my own expense that the group that kidnapped me represents an alarming phenomenon of the revolution: bandit groups like in Somalia that extort the local population," he added.