Would someone please help with hyphenating in the sentences below? Mucosa is a noun in both sentences. Isn't pink-to-pale an adjective compound modifier with a preposition describing mucosa? If so, then what about "slightly erythematous?" Should it too be hyphenated throughout or open after slightly?

The nose shows moderate turbinate edema with pink-to-pale mucosa.

The nose shows moderate turbinate edema with pink-to-slightly-erythematous mucosa.

The nose shows moderate turbinate edema with pink-to-slightly erythematous mucosa.

Question

Would someone please help with hyphenating in the sentences below?  Mucosa is a noun in both sentences.  Isn't pink-to-pale an adjective compound modifier with a preposition describing mucosa?  If so, then what about "slightly erythematous?"  Should it too be hyphenated throughout or open after slightly?

The nose shows moderate turbinate edema with  pink-to-pale mucosa.  

The nose shows moderate turbinate edema with  pink-to-slightly-erythematous mucosa.  

The nose shows moderate turbinate edema with  pink-to-slightly erythematous mucosa.

anonymous · Answer

You should hyphenate words when the entire abdective phrase modifys a noun.  For example, people meet face to face, but they have face-to-face meetings.  In the second instance, face-to-face modifys the word meeting, so it is hyphenated to appear as one word.  How would that definition play into your choices?