Mpox is a viral illness primarily identified by a distinct skin rash. While it can also produce flu-like symptoms, the skin lesions are its most defining feature. Most cases are mild, and the appearance and progression of the rash follow a specific pattern. Understanding this rash is useful for recognition and proper care.
The Appearance and Progression of Lesions
The mpox rash evolves through predictable stages. It begins as flat, pink spots (macules), lasting for one to two days. These spots then become raised bumps called papules, a stage that also persists for about one to two days. The lesions then transform into vesicles, which are small blisters filled with clear fluid.
The vesicles soon fill with an opaque, yellowish fluid, becoming pustules. These pustules are firm, well-circumscribed, deep-seated, and may develop a central dimple, a feature known as umbilication. This stage can be painful and lasts for about a week.
Eventually, the pustules dry up, forming crusts and scabs. This final stage can take a week or two to complete, after which the scabs fall off. A key feature of the mpox rash is that all lesions on a person’s body tend to progress through these stages in unison.
A person is considered contagious until all scabs have fallen off and a new layer of intact skin has formed.
Location and Distribution of the Rash
The mpox rash can appear on nearly any part of the body. Common locations include the face, chest, hands, feet, and areas inside the mouth or in the anogenital region. The rash often begins on the face before spreading to other parts of the body.
A distinctive feature is the appearance of lesions on the palms of the hands and the soles of the feet. The number of lesions can vary significantly from one individual to another, from a few isolated sores to thousands. Recent cases have shown that the rash can sometimes be localized to just a few lesions or a single one.
Differentiating Mpox from Other Skin Conditions
The mpox rash can be mistaken for other skin conditions. For instance, while both mpox and chickenpox cause blistering rashes, chickenpox lesions appear in successive waves. This means a person with chickenpox will simultaneously have spots in various stages of development, such as new bumps, fluid-filled blisters, and crusted scabs.
Syphilis can also produce a rash that affects the palms and soles, but the lesions of secondary syphilis are not vesicular, meaning they do not form blisters. Herpes simplex virus lesions are usually clustered in a specific area and recur in the same location. The mpox rash tends to be more generalized, although localized presentations can occur. Swollen lymph nodes also help distinguish mpox from these other conditions.
Skin Care and Scar Prevention
Proper skin care during an mpox infection can help soothe discomfort and reduce the chance of secondary bacterial infections. Keep the lesions clean by washing with mild soap and water. To manage itching, apply cool compresses or take warm baths, as hot water can dry out the skin and worsen it. Avoid scratching or picking at the lesions, as this can lead to infection and increase the risk of scarring.
Keeping the rash covered with clothing or bandages helps prevent the virus from spreading to other people or other parts of the body. Applying petroleum jelly or a fragrance-free ointment can keep the skin moisturized and may help prevent scars from forming.
After the scabs have fallen off, some people may notice dark spots or scars. Protecting the healed skin from the sun by seeking shade, wearing protective clothing, and using a broad-spectrum sunscreen with an SPF of 30 or higher can help prevent skin discoloration. Additionally, using a silicone-based gel or patch on the healed skin may minimize the appearance of scars.