It is one of the most often asked questions.
P.S. It may be crazy thinking but, could it be frostbite?
ANSWER: This is one of the most often asked question on Poultry and will end up on our FAQ page in a day or two. From what you describe, it does appear to be fowl pox.
Frostbite first appears on the extremities of the comb (the points) and sometimes the toes. Frostbitten tissue does NOT heal or grow back. It dies and falls off and will result in a bird's comb being "rounded off" fairly quickly.
There are several articles on fowl pox on our Poultry Disease Help Page.
This is from Mississippi
"Fowl pox can be transmitted by direct or indirect contact. The virus is highly resistant in dried scabs and under certain conditions may survive for months on contaminated premises. The disease may be transmitted by a number of species of mosquitoes. Mosquitoes can harbor ineffective virus for a month or more after feeding on affected birds. After the infection is introduced, it spreads within the flock by mosquitoes as well as direct and indirect contact. Recovered birds do not remain carriers.
Since fowl pox usually spreads slowly, a flock may be affected for several months. The course of the disease in the individual bird takes three to five weeks. Affected young birds are retarded in growth. Laying birds experience a drop in egg production. Birds of all ages that have oral or respiratory system involvement have difficulty eating and breathing. The disease manifests itself in one or two ways, cutaneous pox (dry form) or diphtheritic pox (wet form).
Dry pox starts as small whitish foci that develop into wart-like nodules. The nodules eventually are sloughed and scab formation precedes final healing. Lesions are most commonly seen on the featherless parts of the body (comb, wattles, ear lobes, eyes, and sometimes the feet).
Wet pox is associated with the oral cavity and the upper respiratory tract, particularly the larynx and trachea. The lesions are diphtheritic in character and involve the mucous membranes to such a degree that when removed, an ulcerated or eroded area is left.
Fowl pox is readily diagnosed on the basis of flock history and presence of typical lesions. In some cases, laboratory diagnosis by tissue or transmission studies is necessary.
There is no treatment for fowl pox. Disease control is accomplished best by preventative vaccination since ordinary management and sanitation practices will not prevent it. Several kinds of vaccines are available and are effective if used properly.
Vaccination of broilers is not usually required unless the mosquito population is high or infections have occurred previously. The chicks may be vaccinated as young as one day of age by using the wing-web method and using a one needle applicator. All replacement chickens are vaccinated against fowl pox when the birds are six to ten weeks of age. One application of fowl pox vaccine results in permanent immunity."