Psoriasis is a chronic autoimmune condition characterized by an accelerated life cycle of skin cells, leading to thick, red, and scaly patches known as plaques. These plaques are often severely dry, itchy, and prone to cracking, compromising the skin’s protective barrier function. Petroleum jelly, a common and inexpensive skincare product, is frequently recommended as a supportive measure in managing these symptoms. While it does not address the underlying immune dysfunction, this simple occlusive agent is considered a helpful component of a psoriasis management plan.
The Role of Occlusion in Psoriasis Management
Petroleum jelly (petrolatum) is an ointment composed of mineral oils and waxes that functions as an effective occlusive moisturizer. Its primary benefit for psoriatic skin stems from its ability to form a physical, semi-impermeable barrier over the skin’s surface. This mechanism of occlusion is crucial for deeply hydrating the damaged skin.
The psoriatic skin barrier is often impaired, resulting in an elevated rate of Transepidermal Water Loss (TEWL). TEWL is the measure of water vapor escaping from the skin, which causes the characteristic dryness and scaling of plaques. Applying petrolatum can dramatically decrease this water loss.
By trapping existing moisture, petrolatum helps to rehydrate the stratum corneum, or outermost layer of the skin, making the thickened plaques softer and more pliable. This physical action reduces scaling, which alleviates associated symptoms like itching and stinging. This moisturizing effect also helps improve the overall integrity of the skin barrier.
This purely physical effect contrasts with medicated topical treatments that target inflammation or cell turnover, such as corticosteroids or retinoids. However, the protective film created by the jelly is also beneficial for enhancing the absorption of these prescribed topical medications. Applying petrolatum over a medicated cream can increase its contact time and penetration, boosting its therapeutic effect.
Effective Application Techniques
Maximizing the soothing and hydrating benefits of petroleum jelly depends on the timing and method of application. The most effective strategy is to apply the ointment when the skin is damp, typically within a few minutes of finishing a bath or shower. Applying the jelly to moist skin ensures that water is sealed into the skin layers before it evaporates.
A common and effective method is the “soak and seal” technique. The skin is soaked in lukewarm water for 10 to 15 minutes, gently patted mostly dry, and then immediately coated with a thick layer of petrolatum. For areas with particularly thick plaques, a generous application is necessary for sufficient coverage and hydration. The ointment should be massaged in gently until a visible sheen remains on the skin.
Advanced Occlusion Methods
Advanced occlusion methods can further enhance the jelly’s performance, particularly for stubborn plaques on the hands, feet, or elbows. This involves applying a thick layer of petroleum jelly and then covering the area with a protective, non-porous material, like plastic wrap or gloves, for several hours or overnight. This wet-wrap technique significantly increases the depth of hydration and promotes the shedding of scales. Wearing protective clothing after application also helps contain the product and prevents the messiness and staining associated with the thick ointment.
When Petroleum Jelly Should Be Avoided
Despite its utility, petroleum jelly is not suitable for all areas or all types of psoriasis. The occlusive nature that makes it effective can also create environments conducive to certain complications. Its thick texture can be messy, and the product is known to stain clothing and bedding, which can discourage consistent use.
Risk of Secondary Infections
Application of petrolatum to areas where skin folds touch, such as the armpits, groin, or under the breasts (where inverse psoriasis commonly occurs), is a concern. In these areas, the occlusive layer traps heat and moisture against the skin. This warm, damp environment can lead to the overgrowth of yeast or fungi, potentially causing secondary infections that exacerbate the psoriatic condition.
Other Considerations
The heavy nature of the ointment can clog pores, so people prone to acne should avoid using it on the face or other acne-prone regions. Another consideration is the risk of folliculitis, a minor infection of the hair follicles, caused by the trapping of bacteria beneath the heavy layer. Furthermore, when the jelly is absorbed into clothing or bandages, it increases the flammability risk, requiring these items to be washed thoroughly.