Kirk Barber, MD, FRCPC

FigureI always find it difficult to speak with pediatricians about diaper rashes. Pediatricians look after many more children with rashes in the diaper area than I do-and all have their own secret ways to treat these children.  

The photos presented this month reveal disease entities I have seen that did not respond to conventional therapy and that became resistant "diaper rashes." You may have seen some of these "bottoms" in previous issues of 

. Next to each photograph, I have given several clues to the diagnosis. See if you can match these clues with the diagnostic choices listed below. You can check to see whether your diagnostic choices are correct on page 61.

 I hope you enjoy the diagnostic challenge.

 
 A. Granuloma gluteale infantum 
 B. Acrodermatitis enteropathica 
 C. Psoriasis with pustules (Candida) 
 D. Histiocytosis X 
 E. Atopic eczema 
 F. Lichen sclerosus et atrophicus 

Yellow-red papules, some of which are eroded and/or purpuric 

Depigmentation in a symmetric pattern about the vulva and perianal skin 

Severe "dermatitis" with erosions and pustules 

May be associated with diarrhea and failure to thrive

Initial improvement with anti-candidal therapy 

Persistence of erythema and maceration about the vulva, perianal, and flexural skin 

Often associated with a family history of psoriasis 

Multiple red-brown papules and nodules, often eroded 

Prolonged use of mid-strength potent corticosteroids in the diaper area 

Spontaneous resolution once the corticosteroids are stopped 

Erythema with scaling on convex surfaces of the thighs and suprapubic skin 

Articles

The photos presented this month reveal disease entities I have seen that did not respond to conventional therapy and that became resistant "diaper rashes." You may have seen some of these "bottoms" in previous issues of Consultant For Pediatricians. Next to each photograph, I have given several clues to the diagnosis. See if you can match these clues with the diagnostic choices listed below. You can check to see whether your diagnostic choices are correct on page 61.

Resistant "Diaper Rashes"

The mother of this school-aged girl is concerned that her child has a fungal infection in her fingernails and that the nails are destroyed forever. Your examination reveals that all 20 of her nail plates are affected similarly.

Case: Trachyonychia (Twenty-Nail Dystrophy)

--the name given to an acquired condition of the nails that often occurs as an isolated event. The more common term used currently for this condition is trachyonychia because the condition may not affect all 20 nails and similar morphological changes in the nail plate have been reported in association with alopecia areata, lichen planus, and psoriasis. The nail plate changes associated with these inflammatory conditions may precede the cutaneous findings by many months, which makes their diagnosis challenging.

I believe that there is an entity termed "twenty-nail dystrophy" that is a benign and idiopathic disorder. The nail plates have a distinct appearance and all 20 nails are dystrophic. The nail plates are lusterless and their surface appears to have been sandpapered in a longitudinal direction. The plates are thin and rough with accentuated longitudinal ridges and the cuticles appear to be "roughed up" and thickened. The free ends of the plates are brittle and rough. The nail plates do not appear to be growing. 

The major parental concerns are for the long-term future of the nails and the possibility of a fungal infection.

If the presentation is typical, I am able to reassure the parents that this is not a fungal infection of the nail plates. However, I often find it necessary to do a fungal culture to support my opinion against all of the medical and nonmedical advice that they have received to the contrary. The use of topical corticosteroids under occlusion has been advocated by some, but I have not found this approach to be successful. For that reason, and because parents tend to over-treat with topical steroids to this area, I am inclined to wait for the spontaneous resolution that almost always occurs over months to years in this childhood variant. I recommend only attention to the manicuring of the plates to avoid "catching" and the use of nail polish for cover if parents wish. 

I advise parents that I believe the condition to be idiopathic, that the nail plates will return to normal as mysteriously as they have changed, that there will not be any scarring, and that nail polish will go on smoothly for their daughter's wedding.	*

Trachyonychia in a School-Aged Girl

his 13-year-old girl comes to your office in tears. Her mother had received a note from school, advising that the nurse had found head lice and nits in her daughter's hair.

The patient's mother wants to cut off her child's hair to eliminate the lice. She is afraid to let her daughter use an insecticide to treat the head lice and asks whether there are any other options.

--is a common problem in schools today. Approximately 3% of school children are affected; this translates into millions of days lost from school every year.

The louse infests only the human head. It simultaneously sucks blood and secretes saliva, which results in an inflammatory reaction and itching. The lice cannot jump or fly, and pets are not a vector. Head-to-head contact is the mode of transmission.

The adult female louse (which lives for approximately 1 month) lays from 1 to 6 eggs per day (

). When the eggs are laid, they are translucent and attach to the hair shaft at the scalp. The eggs hatch in a week, and the nits (which are empty eggshells) remain attached to the shaft. These eggshells move with the hair as it grows at a rate of about 1 cm per month.

The basic principle I follow is not to diagnose an active head lice infestation unless I can find a living, moving louse. If I cannot find a louse on a careful initial inspection of a child's scalp, I teach the parents to "comb for detection." This involves seating the child with a dark cloth draped about his or her shoulders. A plastic or metal fine-tooth comb is then placed in the hair with the tines touching the scalp. The comb is firmly drawn down the hair from the roots to the tips. This action is repeated circumferentially around the scalp until the first louse is detected--either in the comb or on the drape. I think wet hair increases the yield, but this technique is often effective with dry hair as well.

Once the diagnosis is made, then the decision is whether to use insecticides. If the parents wish to avoid insecticides, it is possible to clear up infestations in more than one third of cases with a "wet combing" technique. The setup and actions are similar to those for the "combing for detection" technique, but the hair is first "slicked" with either a hair conditioner or oil--such as peanut or olive oil. The combing should be performed for 30 minutes once or twice daily and repeated every 3 to 4 days; the combing can stop a week after the last louse is discovered. Patients may use their regular shampoo program during this treatment period.

Insecticides offer more effective treatment; success rates exceed 90%. Permethrin, pyrethrin, and malathion are also safe if used properly. Each of these products has specific directions packaged with it. I recommend that these directions be followed exactly--particularly those that direct parents to wet the child's hair thoroughly with the product. I suggest that medication be reapplied in a week and that personal care hair items (eg, bedding, towels, hats, and clothing that the child has worn) be washed and dried at hot temperatures. I also encourage "wet combing" and the removal of nits during the first week after treatment.

Resistance to insecticides--particularly to permethrin and pyrethrin--is becoming an increasing problem (

). Advise patients not to use any insecticide treatment more than twice in a single treatment cycle. Also, a different topical insecticide should be used if reinfestation occurs within the first month after treatment.

It can be difficult to determine whether resistance is present or whether the child has been reinfested. I often ask parents to "wet comb" the child's hair: if there are many lice in various stages of development (ie, nymph to adult), then resistance is likely. And if only a few adult lice are found, then it is probable that they represent reinfestation.

Some practical points I share with parents:

•All household members should be checked at home or in the clinic, but I believe that only those who are infested need to be treated.

•I believe that a child may return to school after the first treatment--particularly if an insecticide is used.

•I advise parents that cutting or shaving their child's hair does little, if anything, to improve the success of therapy.

Oral trimethoprim/sulfamethoxazole and ivermectin have both been used successfully to treat head lice. Neither of these agents is approved for this indication, but either may be useful if all topical therapy fails.	*

A 13-year-old girl comes to your office in tears. Her mother wants to cut off her hair.

Focus on Head Lice

This skin condition is present at birth and usually has significant systemic manifestations. Would you be able to identify it in the nursery?

These color changes have been present on this child's skin since her birth. Her parents wonder whether anything can be done to "even out" the coloring.

What is this condition--and what will you tell the child's parents?

is an X-linked dominant disorder that affects the skin, bones, and nerves. The manifestations are present at birth, and the cutaneous findings are characteristic.

The lesions have 4 distinct phases that may overlap or manifest sequentially as follows:

The first (inflammatory) phase is usually present at or within 2 weeks of birth. Lesions must be differentiated from other blistering diseases of the newborn period--especially infections, such as herpes simplex. The blisters appear on an erythematous base and develop in crops over the trunk and extremities, often along the lines of Blaschko. A biopsy specimen taken during this phase will show epidermal vesicles with eosinophils as the predominant type of inflammatory cell. This phase generally resolves within the first 6 months of life.

The second (keratotic) phase is characterized by warty papules that appear in a linear pattern over the extremities. These papules may overlap with the inflammatory phase and generally resolve spontaneously within the first 2 years of life (

The third (hyperpigmented) phase is the most familiar. Linear bands of brown, blue, or gray hyperpigmentation appear in whorls and swirls that conform to the lines of Blaschko. The pigmentation usually continues to appear over the first 2 years of life: it then stabilizes and begins to fade as puberty approaches. Most children lose their pigmentation entirely. The pigmentation does not necessarily follow the exact pattern of the first 2 phases, but will follow the lines of Blaschko.

Atrophy, scarring, and hypopigmentation are the predominant clinical features during the fourth phase. Lesions can occur anywhere on the body.

Dental (75%), neurological (30%), and ophthalmological (35%) manifestations are the most commonly associated systemic issues. Children whose condition is diagnosed in the nursery should be assessed by an ophthalmologist. Retinal vascular proliferation is the most common ocular finding and may result in retinal detachment and blindness.

 a manifestation of pigmentary mosaicism. The hypopigmentation, the only cutaneous abnormality, is present at birth. The morphology is described as "splashed paint," and large surface areas are usually involved. Affected children do not typically have any associated systemic abnormalities, but there are rare reports of asso-ciated ocular and neurological abnormalities.

The pigmentary changes follow the lines of Blaschko. These lines were described in 1901 by Dr Alfred Blaschko when he presented his observations on linear dermatosis. He noted that the lines did not follow any known anatomic structures. Subsequent studies appear to prove his hypothesis that these lines have an embryonic origin.

The lines of Blaschko form a "V" over the vertebral column, an open "S" shape on the sides of the torso and lower abdomen, and an inverted "U" on the anterior arm and adjacent chest wall. They assume a linear (nondermatomal) pattern on the extremities.

There is currently no way to alter the pigmentation.	*

 Happle R. Mosaicism in human skin. Understanding the patterns and mechanisms. 

Author | Kirk Barber, MD, FRCPC

Articles

Resistant "Diaper Rashes"

Trachyonychia in a School-Aged Girl

Focus on Head Lice

Incontinentia Pigmenti and Hypomelanosis of Ito