staphylococcal infection

What is causing this man's lip to slowly erode?

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Case 1: This crusted eroded area on the lower lip of a 67-year-old man has been present for several months.
           
                
  
                                
                                          
Which of the following statements are true?

A. This condition preferentially affects the lower lip.

B. It is more common in women.

C. It is more common in immunocompromised patients.

D. It is more likely to metastasize than similar lesions on nonmucosal surfaces.

E. 5-Fluorouracil is contraindicated in this location.

Case 1: This patient has actinic cheilitis, an actinic keratosis that occurs on the lower lip. A, C, and D are true. Actinic cheilitis is more common in men and in immunocompromised patients. It has a greater propensity to metastasize than keratoses in other locations and is associated with significant mortality when metastasis occurs. Accepted treatments include 5-fluorouracil, cryosurgery, and surgical excision.



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Case 2: A 44-year-old woman with long-standing eczema presents with an exacerbation that consists of tender crusted lesions on the face.

 

 

What is the most likely cause of the exacerbation?

A. Herpes simplex.

B. Candidiasis.

C. Streptococcal infection.

D. Staphylococcal infection.

E. Factitial disease. Your approach will likely include:

F. Bacterial culture.

G. Fungal culture.

H. Herpes culture.

I. Biopsy.

J. Psychiatric consultation.

Case 2: A bacterial culture grew Staphylococcus aureus, D; staphylococcal infection is more common in atopic persons than in persons who do not have atopy-as is candidiasis. In persons with atopy, herpes simplex presents on rare occasions with extensive involvement that occurs within the usual area of distribution of the patient’s eczema. It is not unreasonable to pan-culture (ie, to order bacterial, F, fungal, G, and herpes, H, cultures at the same time) if the diagnosis is uncertain.

This patient’s eruption rapidly responded to a course of cephalexin. If the infection recurs, treatment for nasal carriage of S aureus (eg, mupirocin ointment twice a day for a week) is appropriate.


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Case 3: A 52-year-old woman who has recently returned from a week at a dude ranch complains of a pruritic rash on the back of 1 heel. Neither clotrimazole nor 1% hydrocortisone brought relief. She recently purchased a new pair of shoes.

 

      

To what do you attribute the patient’s rash?

A. Dyshidrosis.

B. Contact dermatitis.

C. Candidiasis.

D. Dermatophyte infection (tinea pedis).

E. Insect bite reaction.

Bonus question: What are the flesh-colored papules on the heel below the rash?

Case 3: A potassium hydroxide preparation of a lesion was positive for dermatophyte infection, D. Application of a topical allylamine antifungal cream was curative. Dyshidrosis is usually symmetric and erupts along the edges of the sole. Contact dermatitis to shoes typically manifests on the dorsum of the foot; in addition, because this patient’s rash did not affect both heels, it was unlikely to be related to her new shoes. Candidiasis is not likely to be found on the feet. Insect bite reactions usually occur on the exposed part of the ankle.

Answer to bonus question: These are piezogenic papules, which result from herniation of fat through the dermis. The papules, which generally occur bilaterally, become apparent on weight bearing and are most often asymptomatic.


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Case 4: The solitary yellow-orange papule above this 2-year-old's eyelid has been present for a month. It does not appear to itch or cause any discomfort.
                
Can you identify the entity underlying this cutaneous lesion?

Case 4: This lesion is juvenile xanthogranuloma, a benign histiocytic infiltration of the skin that produces 1 or more asymptomatic yellowish to orange papules. The clinical impression was confirmed by biopsy, which showed typical nodular histiocytic proliferation and foam cells.

Juvenile xanthogranuloma generally appears in the first year of life-most frequently on the head and neck-and may last for 3 to 6 years before undergoing spontaneous involution. Ophthalmologic examination is recommended, because the lesions may affect the eye-the uvea in particular-during infancy, resulting in hemorrhage and glaucoma. In this case, the pediatric ophthalmologist found no abnormalities in the child’s eyes. The biopsy was curative, and no further treatment was indicated.