Yes, most definitely.
Many people who live, or have lived, in toxic mold-infested homes report severe rashes and hives appearing on their bodies, many overnight. Toxic mold is extremely contagious and extremely dangerous and can even be deadly, especially amongst children and the elderly and infirm. The mold is particularly prevalent in homes that are susceptible to damp and those where the wall lining is non-porous, denying it of oxygen, thus giving the wall no opportunity to breath. Toxic mold, or stachbybotrys chartarum to give it its scientific name, occurs when water damage, excessive humidity, water leaks, condensation or flooding is present.
Treatment of mold allergy hives varies on the severity of the complaint. You could try over the counter medicines that are available at chemists and drugstores, or antihistamines that can be taken to treat symptoms such as hives and rashes. Soothing creams can be used to reduce the itchiness of the hives but, in more serious cases, steroids will be prescribed by your doctor, however these can have side effects.
If you believe toxic mold is present in your home, a thorough home inspection will be able to uncover the dangerous mold form, which should be professionally treated. Toxic molds produce chemicals called mycotoxins that not only cause hives and rashes, but can also bring on seizures, respiratory problems, unusual bleeding and severe fatigue. Toxic mold will only grow on wood, paper and cotton products, but a mold-infested home can become a lethal environment for those prone to allergy problems. Once black mold begins to fester in a home, spores are released by the mold clusters. These microscopic cells quickly become airborne and travel through air conditioning and heating systems. In many cases the only solution to the problem is to demolish the building and rebuild.