Tuesday, July 29, 2008

Scalp Lesion in a Child

Abstract: 14 yo boy with alopecic area since birth
History: Shortly after birth the mother noted a yellowish alopecic area on the scalp. She was told it was from a scalp electrode and thought no more about it. About a year ago, the lesion became more raised and the surface pebbly (bossilated).
O/E: Five cm oval tan/pinkish alopecic plaque with a slightly bossilated surface.
Clinical Photo(s):

Lab: N/A
Histopathology:The epidermis shows papillomatous hyperplasia. In the dermis, the numbers of mature sebaceous glands are increased. Ectopic apocrine glands are often found in the deep dermis beneath sebaceous glands.

Diagnosis or DDx: Nevus Sebaceous of Jadasshon
Reason(s): Presented: You will all see these lesions. It is satisfying to give parents a good explanation and possibly a reference (#1) to read.
References:
1. Dermnet
2. eMedicine
3. Cribier B, Scrivener Y, Grosshans E.
Tumors arising in nevus sebaceus: A study of 596 cases.
J Am Acad Dermatol. 2000 Feb;42(2 Pt 1):263-8.
The rate of malignant tumors arising on NS was very low and we did not observe such cases in children, who had associated benign tumors in only 1.7% of cases. Benign neoplasms were common and most of them occurred on the scalp; this was not a bias resulting from a longer duration before surgery. Because most tumors occurred in adults older than 40 years, our study suggests that prophylactic surgery in young children is of uncertain benefit. Clinical follow-up is probably sufficient, and even those cases with clinical changes often proved to be benign tumors or warts.

4. Santibanez-Gallerani A, Marshall D, Duarte AM, Melnick SJ, Thaller S.
Should nevus sebaceus of Jadassohn in children be excised? A study of 757 cases, and literature review.
J Craniofac Surg. 2003 Sep;14(5):658-60
The incidence of basal cell carcinoma and the need for prophylactic excision in children with nevus sebaceus of Jadassohn have been a topic of controversy. The authors performed a retrospective analysis of 757 cases from 1996 to 2002 in children aged 16 years or younger. No cases of basal cell cancer were found in the nevus sebaceus group. Recent studies in children corroborate these findings and question the need for prophylactic surgical removal of the nevus sebaceus.

Take-Home Points:
1. Most sebaceous nevi will have a benign behavior. There is no crying need for excision at a young age.
2. These lesions have a characteristic appearance and can be diagnosed clinically.
3. They get thicker and more irregular at puberty as a result of hormones acting on the sebaceous glands

Two additional patients seen in Williamstown with N. sebacsous

Thursday, July 3, 2008

Bizarre Hyperpigmented Streaks

Abstract: 30 y.o. man with three week history of hyperpigmented streaks over hip

History: The patient's brother was seen for an unrelated problem and asked if I would look at a picture on his cell phone. His brother, a 30-year-old man, recently returned from the Bahamas where he developed a pruritic inflammatory skin disorder. The cell phone image was hazy, but interesting and I asked if his brother could come in that day. He did, and anamnesis revealed that he had been drinking Corona beer with lime and remembers rubbing his abdomen at that time. Twenty-four to 36 hours later, he developed blisters and erythema at the site where he rubbed his skin. He thought it was from the limes, but his friends told him this was fanciful.

O/E: The examination showed streaky erythema on the right hip. The lesions are along the lines of where he rubbed with his fingers.
Clinical Photo(s)
Brother will cell-phone


Patient demonstrating how he remembers rubbing his abdomen.



Lab: N/A
Histopathology: N/A
Diagnosis or DDx: Phytophotocontact Dermatitis due to Lime (Rutaceae)
Questions: N/A
Reason(s) Presented: Presented for interest. It would be possible for a patient to send an image to his dermatologist from the Bahamas on his cell phone and a tentative diagnosis arrived at. Knowing that limes contain furocoumarin (a potent photosensitizer) could have led to a more timely diagnosis. If treatment was initiated very early, some of the post-inflammatory hyperpigmentation might have been avoided. At that time, wet compresses and topical corticosteroids could have shortened the course of the inflammation.
Discussion: See reference. Limes, lemons and a number of other plants contain furocoumarin. To develop phytophotocontact dermatitis, an individual needs to have contact with the agent and then get sun-exposure before washing the skin. Then, 24 - 36 hours later an exaggerated sunburn develops which heals with post-inflammatory hyperpigmentaton. The pigment change is more pronounced in darker individuals and can last many months. It usually fades over time.

Reference: Hyperpigmented Macules and Streaks

Wednesday, July 2, 2008

Dermatologic Vignette

Abstract: 75 yo woman with 3 week history of a rash.
History: Painful rash in groin. Healthy woman. Was on antibiotics around a month ago. She used a topical cream given for another purpose by her Gyn. (It turns out the cream she had been using was clobetasol -- a super potent corticosteroid)
O/E: Firey erythema of crural folds, pubic area. Studded with fine superficial pustules.
Clinical Photo(s)

Lab: KOH prep from pustule loaded with budding heasts
Histopathology: N/A
Diagnosis or DDx: Candidiasis (Candidal Intertrigo: iatrogenic)
Reason(s) Presented: For interest. Rick factors for candida intertrigo include antibiotics, diabetes, topical and oral steroids, OCP, pregnancy. This patient took antibiotics and was applying a superpotent corticosteroid to the area. The latter acts as fertilizer for the yeast.
Reference: emedicine.com