What could be the cause of a growing lump on my lower back after an injury?

The contact dermatitis can last a long time. It depends upon the nature, frequency and duration of the exposure to the allergens. If the exposure to the allergens continues it might take very long time. If the exposure to the allergens is stopped then it will be recovered quickly.

If its only acne marks, continuing your acne treatment with facewash and gels will improve it. Some topical agents also helps in removing the pigmentation and marks of the acne. Even Salic acid 20% gel at night on spots is helpful. Glyco 6 or Glycolic acid 6% is recommended for application on the face. Acne compatible sunscreen is also helpful. Chemical Peeling with glycolic acid or salicylic acid is useful

The numerous factors that lead to skin allergies on the backside and legs include irritants, allergenic agents, infection or autoimmune disorders. It is necessary to consult a dermatologist that will conduct sufficiently comprehensive evaluation and suggest adequate options for treatment. Self-diagnosis and self treatment can make the situation only worse complicating it.

Vitiligo is a condition where white patches develop on the skin and face. It occurs when cells that produce color for our skin die. Common signs include white spots appearing especially in areas exposed to sun. The root cause is not fully understood but it may be linked to problems with the immune system. Treatment options comprise using topical steroids, light therapy, and skin grafts. It is important to wear sunscreen to protect affected parts.

Creamy cleanser( low level of PH)  will be good for skin that is dry  and for part of your skin that is oily(nose) foaming cleanser will be good. But use moisturizer later. I hope this proved helpful. 

It seems like you’ve got post-inflammatory hyperpigmentation after popping your zits. These can result in dark marks on your face. To fade them away, consider trying out products that contain vitamin C, niacinamide, or kojic acid as ingredients. Sun protection is key since UV rays can worsen the appearance of these spots. Also, remember not to irritate your skin further to avoid more dark spots.