DISCUSSION
This is the way seborrheic dermatitis (SD) acts: It sits around for years, causing minor problems in common areas (eg, face, scalp, ears, and beard). Then the stress of life intrudes, the candle is being burnt from both ends, and SD blossoms, appearing in places such as the chest, groin, suprapubic area, axillae, and genitals.
On the genitals, SD is often bright red, with little if any scale. Why? The moisture and friction particular to the genital and intertriginous (skin on skin) areas prevent scale from accumulating.
Penile rashes generally get everyone’s attention, including that of the patient’s sexual partner(s). For the average nonclinician, the list of possible explanations is infinite—and worrisome. The situation is, in some ways, worse for the average primary care provider, who will almost always decree such a rash a “yeast infection” (though it seldom responds to anti-yeast medications—for good reason: Otherwise healthy circumcised men almost never develop yeast infections anywhere, let alone on the penis).
If you remove “yeast” from the differential, the average primary care provider will be lost. An abbreviated differential list for penile rashes and conditions includes:
• Psoriasis
• Seborrhea
• Contact vs irritant dermatitis
• Eczema/lichen simplex chronicus
• Lichen sclerosis et atrophicus (traditionally termed balanitis xerotica obliterans or BXO when it occurs on the penis)
• Lichen planus
• Reiter syndrome
• Scabies
• Erythroplasia of Queyrat (superficial squamous cell carcinoma)
• Melanoma
• Herpes simplex
• Molluscum
• Pearly penile papules
• Tyson’s glands (prominent pilosebaceous glands on the penile shaft)
• Angiokeratoma of Fordyce
• Condyloma accuminata
• Primary syphilis chancre
• Fixed-drug eruption
(Note that while yeast is not on this list, it certainly could be considered in an uncircumcised hyperglycemic patient.)
The top five items on the list would cover 90% of patients with penile rashes. Seborrheic dermatitis is utterly common but only rarely recognized when it occurs in unusual areas (as in this case).
For this patient, I prescribed topical hydrocortisone 2.5% cream (to be applied bid to all affected areas) and advised him to shampoo the areas daily with ketoconazole-containing shampoo. But the main thing I did for him, and his wife, was provide peace of mind about all the terrible conditions he didn’t have. With treatment, his penile lesions resolved within two weeks.
TAKE-HOME LEARNING POINTS
• Seborrheic dermatitis (SD) is common in the scalp, on the face, and in the ears, but it can also appear on the chest, axillae, or genitals.
• Yeast infections are quite uncommon in otherwise healthy men.
• Stress is often a triggering factor with worsening SD.
• Asking about and finding corroborative areas of involvement (face, ears, brows, scalp) can help in diagnosing atypical cases of SD.