For a small patch (under one square foot/30cm x 30cm), you can attempt DIY removal if you have no significant health concerns. Use a dedicated mold remover or a solution of white vinegar and water, not bleach, as bleach only removes surface discoloration and does not kill the roots. Wear an N95 mask, gloves, and goggles to protect yourself from spores. Thoroughly clean the area, dry it completely with a fan, and address the moisture source—this is often inadequate air circulation. Move the shelving unit slightly away from the wall to allow air to flow.

However, given your asthma and the fact the mold is on a structural wall (likely cold from AC, causing condensation), a professional assessment is strongly recommended. In villas, what you see on the surface can be a sign of a larger problem within the wall cavity. Professionals use moisture meters and thermal imaging to find the hidden extent of the moisture and can perform air or surface sampling to identify the mold species, which is important for understanding potential health risks and the correct remediation protocol. For health-sensitive individuals and larger infestations, the controlled containment and professional-grade air scrubbing used by certified remediators are necessary to prevent spreading spores throughout your home. The goal is to fix the moisture problem and remove the mold, not just clean the visible stain.