Topical compositions comprising polyunsaturated fatty acids

A method of treating eczema in a mammal, the method comprising administering to the mammal a composition comprising a compound of Formula (I):

• or a pharmaceutically acceptable salt thereof;
• wherein
• -Alk- is —(CH2)3-[cis]CH═CH—CH2-[cis]CH═CH-[trans]CH═CH—CH(OR2)—;
• R1 is selected from the group consisting of:
• hydrogen;
• C1-C6 alkyl;
• C2-C6 alkenyl;
• C2-C6 alkynyl;
• C6-C10 aryl;
• 5- to 10-membered heteroaryl;
• C3-C7 carbocyclyl or 5- to 10-membered heterocyclyl group;
• a group of formula —CH2—CH(OR3)—CH2—(OR4) wherein R3 and R4 are each independently hydrogen atoms or —(C═O)—R6, wherein R6 is an aliphatic group having from 3 to 29 carbon atoms;
• and a group of formula —(CH2OCH2)mOH, wherein m is an integer from 1 to 200;
• R2 is selected from the group consisting of:
• a hydrogen atom;
• a group of formula —(C═O)—R5, wherein R5 is a C1-C6 alkyl, C2-C6 alkenyl, C2-C6 alkynyl, C6-C10 aryl, 5- to 10-membered heteroaryl, C3-C7 carbocyclyl or 5- to 10-membered heterocyclyl group;
• an aliphatic group having from 3 to 29 carbon atoms;
• and
• a group of formula —(CH2OCH2)mOH, wherein n is an integer of from 1 to 200;
• and
• wherein said alkyl, alkenyl, alkynyl and aliphatic groups are the same or different and are each unsubstituted or substituted with 1, 2 or 3 unsubstituted substituents which are the same or different and are selected from halogen atoms and C1-C4 alkoxy, C2-C4 alkenyloxy, C1-C4 haloalkyl, C2-C4 haloalkenyl, C1-C4 haloalkoxy, C2-C4 haloalkenyloxy, hydroxyl, —SR′, and —NR′R″ groups where R′ and R″ are the same or different and represent hydrogen or unsubstituted C1-C2 alkyl;
• said aryl, heteroaryl, carbocyclyl and heterocyclyl groups are the same or different and are each unsubstituted or substituted by 1, 2, 3 or 4 unsubstituted substituents which are the same or different and are selected from halogen atoms, and cyano, nitro, C1-C4 alkyl, C1-C4 alkoxy, C2-C4 alkenyl, C2-C4 alkenyloxy, C1-C4 haloalkyl, C2-C4 haloalkenyl, C1-C4 haloalkoxy, C2-C4 haloalkenyloxy, hydroxyl, C1-C4 hydroxyalkyl, —SR′ and —NR′R″ groups wherein each R′ and R″ is the same or different and represents hydrogen or unsubstituted C1-C4 alkyl, and
• wherein the composition is topically administered in an amount sufficient to deliver 0.00001 g to 10 g of the compound per square meter of skin.