Frequently used combinations include the following: antibiotic and benzoyl peroxide, antibiotic and topical retinoid, or topical retinoid and benzoyl peroxide. Dermatologists generally prefer combining benzoyl peroxide with a retinoid over the combination of a topical antibiotic with a retinoid. Both regimens are effective, but benzoyl peroxide does not lead to antibiotic resistance. Pregnancy
Although sebaceous gland activity in the skin increases during the late stages of pregnancy, pregnancy has not been reliably associated with worsened acne severity. In general, topically applied medications are considered the first-line approach to acne treatment during pregnancy, as they have little systemic absorption and are therefore unlikely to harm a developing fetus. Highly recommended therapies include topically applied benzoyl peroxide (pregnancy category C) and azelaic acid (category B). Salicylic acid carries a category C safety rating due to higher systemic absorption (9–25%), and an association between the use of anti-inflammatory medications in the third trimester and adverse effects to the developing fetus including too little amniotic fluid in the uterus and early closure of the babies ductus arteriosus blood vessel. Prolonged use of salicylic acid over significant areas of the skin or under occlusive (sealed) dressings is not recommended as these methods increase systemic absorption and the potential for fetal harm. Tretinoin (category C) and adapalene (category C) are very poorly absorbed, but certain studies have suggested teratogenic effects in the first trimester. The data examining the association between maternal topical retinoid exposure in the first trimester of pregnancy and adverse pregnancy outcomes is limited.
Projecting on either side are the lateral and medial epicondyles. Articular surface
The articular surface extends a little lower than the epicondyles, and is curved slightly forward; its medial extremity occupies a lower level than the lateral. The lateral portion of this surface consists of a smooth, rounded eminence, named the capitulum of the humerus; it articulates with the cup-shaped depression on the head of the radius, and is limited to the front and lower part of the bone. Fossae
Above the front part of the trochlea is a small depression, the coronoid fossa, which receives the coronoid process of the ulna during flexion of the forearm. Above the back part of the trochlea is a deep triangular depression, the olecranon fossa, in which the summit of the olecranon is received in extension of the forearm. The coronoid fossa is the medial hollow part on the anterior surface of the distal humerus. The coronoid fossa is smaller than the olecranon fossa and receives the coronoid process of the ulna during maximum flexion of the elbow. Above the front part of the capitulum is a slight depression, the radial fossa, which receives the anterior border of the head of the radius, when the forearm is flexed. These fossæ are separated from one another by a thin, transparent lamina of bone, which is sometimes perforated by a supratrochlear foramen; they are lined in the fresh state by the synovial membrane of the elbow-joint, and their margins afford attachment to the anterior and posterior ligaments of this articulation.