This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Unknown
The below rash was seen in a person. He has a family history of asthma. What could be the most probable diagnosis? 
Select and explain. 
A. Seborrheic dermatitis, B. Atopic dermatitis, C. Allergic contact dermatitis, D. Erysipelas
C: Allergic contact dermatitis
Answer: C: Allergic contact dermatitis 
Explanation: Ref. Rook's Textbook of Dermatology, Pg 99
 
Allergic contact dermatitis is a form of dermatitis/eczema caused by an allergic reaction to a material, called an allergen, in contact with the skin.
Pathogenesis

Allergic contact dermatitis is a type 4 or delayed hypersensitivity reaction and occurs 48–72 hours after exposure to the allergen.  
The mechanism involves CD4+ T-lymphocytes, which recognise an antigen on the skin surface, releasing cytokines that activate the immune system and cause the dermatitis.