Calotropis gigantea, commonly known as crown flower or "arka" in Ayurvedic medicine, has a long history of traditional use for various skin ailments, including eczema. In traditional systems such as Ayurveda and folk medicine across India and Southeast Asia, leaves, latex, and extracts of Calotropis gigantea have been applied topically to treat dermatitis, eczema, and other inflammatory skin disorders. The rationale for its use stems from the plant’s reputed anti-inflammatory, antimicrobial, and wound-healing properties as described in ancient texts and ethnobotanical surveys.

Scientific studies on Calotropis gigantea are limited but suggest the presence of bioactive compounds such as flavonoids, triterpenoids, and cardenolides that exhibit anti-inflammatory and antimicrobial activity in vitro and in animal models. However, direct clinical evidence supporting its efficacy specifically for eczema in humans is lacking. Most of the available research focuses on general skin healing and inflammation models rather than controlled eczema trials. Furthermore, the latex and other parts of the plant can be irritating or even toxic if improperly used, which warrants caution.

In summary, the use of Calotropis gigantea for eczema is primarily supported by traditional usage with limited preclinical scientific data. Robust clinical trials validating its efficacy and safety for eczema are not currently available.