This first bowl describes the plague in only one verse. It is a plague of a “loathsome and malignant sore on [all] the people who had the mark of the beast and who worshipped his image.” We can’t be exactly sure what this plague will be like, but we can get a good idea of its nature from three sources: from Job (Job 2:7), from the sixth plague of Egypt (Ex. 9:9-11), and from the story of the rich man and Lazarus (Lu. 16:20-21).
First of all, we know that in these three cases, the word for “sore” is the same as in this bowl judgment. In the New Testament case with Lazarus, it is the same Greek word helkos; and in the two Old Testament references, the same Greek word from the Septuagint is used.
In the earliest case of Job, the plague is described as “sore boils from the sole of his foot to the crown of his head.” It was a terrible infection of the skin directly caused by Satan, to test his loyalty to God. In this particular case, Job found some relief from his suffering by scraping his boils with a piece of broken pottery, perhaps to break the boils open and release the infection.
In the case of the sixth plague on Egypt, it is said to be “boils breaking out with sores on man and beast.” Here it seems to be the same as in Job’s case and in the Tribulation, except here the animals will be infected too.
Putting these together, we may conclude that in the Tribulation the sores will be similar, but I can’t help thinking that it may be worse. And though it will be a punishment by the Lord, He may use a man-made means to cause the boils like radioactivity in the air. Hal Lindsey writes,
This rash of malignant sores could easily be caused by the tremendous radioactive pollution in the atmosphere. After the bombings of Nagasaki and Hiroshima thousands of people developed hideous sores because of the radioactivity.
As to the duration of this first bowl-plague, we can’t be sure that it will last for the entire length of the Great Tribulation (for three and a half years); however, it seems clear from verse eleven, that during the fifth bowl, people will still be suffering from their sores.
But there is one thing we can be sure of; the plague will affect only those unbelievers that took the mark of the beast and who worship his image. All true believers will be supernaturally protected as were the Jews in Egypt in the days of Moses.