Unexpected Source for Itch

 A 70-year-old man is referred to dermatology for evaluation of a scalp rash that has been present for months. Complaining bitterly of the itching in his scalp, he gives a history that includes treatment attempts with a number of medications, including prescription ketoconazole shampoo, oral antibiotics (eg, minocycline), and a course of oral terbinafine (250 mg/d for three weeks)—none of which has had a positive impact on the problem.

His wife, who is with him, at first denies and then finally admits to having an itchy scalp as well. Neither has a history of prior skin problems. 

The patient’s history is significant for type 2 diabetes and for well-controlled hypertension. He has been retired for many years and lives at home with his wife.

EXAMINATION
The patient appears disheveled, confused, and dirty. He is grossly oriented as to time and place, but hard of hearing and difficult to communicate with as a result.

His hair is greasy and dirty, as well as matted down in places. On closer inspection, scabs are noted in his scalp; they are widely distributed but especially heavy in the occipital and supra-auricular scalp. Many flakes of dandruff (some quite large) can also be seen.

Raising the thick hair over his nuchal scalp reveals a whitish sheen. Under 10x magnification, multiple tiny white papules are observed attached to each hair shaft, which accounts for the sheen. When examined under the microscope, the papules are clearly identified as nits. No adult lice are noted.

Significant tender adenopathy is elicited on palpation of the posterior neck area.

Continue reading for the discussion... 

DISCUSSION
Clearly, the basic problem is head lice (pediculosis capitis), with everything else stemming from it. This can be quite confusing for many reasons, not least of which is that one thinks of head lice as a pediatric problem.

The related issue is bacterial infection secondary to scratching and picking, usually from coagulase-negative staph. Minocycline or trimethoprim/sulfa would have been adequate for treatment but of course would not address the main problem: the lice. 

Ironically, one of the other impediments to a correct diagnosis was the severity of this patient’s case. It was, without a doubt, the worst I’ve seen in a 30-year career. The nits were so numerous as to render them almost impossible to see without magnification.

There’s little doubt that his wife had them too, adding to the potential for others (eg, grandchildren) around them to be infested as well. Furthermore, this represented a source for re-infestation despite treatment efforts.

Luckily, neither the organisms nor the nits remain viable for long off the body, which means they cannot reside and replicate on inanimate objects. Nonhumans cannot give or get human head lice. Given the organism’s need for warmth and aversion to light, there’s little chance for involvement in areas other than the scalp.

Both the patient and his wife were treated with oral and topical ivermectin. The topical form is applied once to a damp scalp, left on for 10 minutes, then rinsed out. It not only kills the adult organisms but also appears to render the nits nonviable—potentially obviating the necessity of using a nit comb.

The oral ivermectin (150 µg/kg ) was prescribed as follows: four 3-mg tablets now and another four tablets in 10 days to kill any remaining adults. Oral ivermectin is usually not necessary in the treatment of head lice and was only used in this case because of the severity.

Since their cases were so severe, I also advised them both to consider shaving their heads first to facilitate effective treatment. Again, this step is seldom necessary except in the most extreme cases. However, it also facilitated management of their secondary pyoderma, which was treated with trimethoprim/sulfa (double strength, bid for a week).

Since the itching caused by head lice is essentially an allergic reaction to the organism’s protein, that symptom may persist for some time, albeit with gradually diminishing intensity.

Continue reading for Joe Monroe's take-home learning points... 

TAKE-HOME LEARNING POINTS

• Pediculosis capitis (head lice) is seen mostly in children but affects adults as well.

• Pyoderma, secondary to scratching, can mislead the diagnostician and thereby delay diagnosis of the underlying problem.

• Oral trimethoprim/sulfa is often used to treat lice-associated pyoderma but does nothing directly to kill the lice themselves.

• The itching from head lice is a delayed hypersensitivity reaction to the lice protein and can take months after infestation to develop.

• Conversely, itching will develop early on in patients who have been sensitized by having had head lice in the past.

• The use of topical ivermectin has proven to be exceptionally effective in clinical trials.

DISCLOSURE: The author discloses having spoken and written about topical ivermectin at the behest of the manufacturer, but this article was not part of that process, nor is it supported by the product’s manufacturer in any way.

 A 70-year-old man is referred to dermatology for evaluation of a scalp rash that has been present for months. Complaining bitterly of the itching in his scalp, he gives a history that includes treatment attempts with a number of medications, including prescription ketoconazole shampoo, oral antibiotics (eg, minocycline), and a course of oral terbinafine (250 mg/d for three weeks)—none of which has had a positive impact on the problem.

His wife, who is with him, at first denies and then finally admits to having an itchy scalp as well. Neither has a history of prior skin problems. 

The patient’s history is significant for type 2 diabetes and for well-controlled hypertension. He has been retired for many years and lives at home with his wife.

EXAMINATION
The patient appears disheveled, confused, and dirty. He is grossly oriented as to time and place, but hard of hearing and difficult to communicate with as a result.

His hair is greasy and dirty, as well as matted down in places. On closer inspection, scabs are noted in his scalp; they are widely distributed but especially heavy in the occipital and supra-auricular scalp. Many flakes of dandruff (some quite large) can also be seen.

Raising the thick hair over his nuchal scalp reveals a whitish sheen. Under 10x magnification, multiple tiny white papules are observed attached to each hair shaft, which accounts for the sheen. When examined under the microscope, the papules are clearly identified as nits. No adult lice are noted.

Significant tender adenopathy is elicited on palpation of the posterior neck area.

Continue reading for the discussion... 

DISCUSSION
Clearly, the basic problem is head lice (pediculosis capitis), with everything else stemming from it. This can be quite confusing for many reasons, not least of which is that one thinks of head lice as a pediatric problem.

The related issue is bacterial infection secondary to scratching and picking, usually from coagulase-negative staph. Minocycline or trimethoprim/sulfa would have been adequate for treatment but of course would not address the main problem: the lice. 

Ironically, one of the other impediments to a correct diagnosis was the severity of this patient’s case. It was, without a doubt, the worst I’ve seen in a 30-year career. The nits were so numerous as to render them almost impossible to see without magnification.

There’s little doubt that his wife had them too, adding to the potential for others (eg, grandchildren) around them to be infested as well. Furthermore, this represented a source for re-infestation despite treatment efforts.

Luckily, neither the organisms nor the nits remain viable for long off the body, which means they cannot reside and replicate on inanimate objects. Nonhumans cannot give or get human head lice. Given the organism’s need for warmth and aversion to light, there’s little chance for involvement in areas other than the scalp.

Both the patient and his wife were treated with oral and topical ivermectin. The topical form is applied once to a damp scalp, left on for 10 minutes, then rinsed out. It not only kills the adult organisms but also appears to render the nits nonviable—potentially obviating the necessity of using a nit comb.

The oral ivermectin (150 µg/kg ) was prescribed as follows: four 3-mg tablets now and another four tablets in 10 days to kill any remaining adults. Oral ivermectin is usually not necessary in the treatment of head lice and was only used in this case because of the severity.

Since their cases were so severe, I also advised them both to consider shaving their heads first to facilitate effective treatment. Again, this step is seldom necessary except in the most extreme cases. However, it also facilitated management of their secondary pyoderma, which was treated with trimethoprim/sulfa (double strength, bid for a week).

Since the itching caused by head lice is essentially an allergic reaction to the organism’s protein, that symptom may persist for some time, albeit with gradually diminishing intensity.

Continue reading for Joe Monroe's take-home learning points... 

TAKE-HOME LEARNING POINTS

• Pediculosis capitis (head lice) is seen mostly in children but affects adults as well.

• Pyoderma, secondary to scratching, can mislead the diagnostician and thereby delay diagnosis of the underlying problem.

• Oral trimethoprim/sulfa is often used to treat lice-associated pyoderma but does nothing directly to kill the lice themselves.

• The itching from head lice is a delayed hypersensitivity reaction to the lice protein and can take months after infestation to develop.

• Conversely, itching will develop early on in patients who have been sensitized by having had head lice in the past.

• The use of topical ivermectin has proven to be exceptionally effective in clinical trials.

DISCLOSURE: The author discloses having spoken and written about topical ivermectin at the behest of the manufacturer, but this article was not part of that process, nor is it supported by the product’s manufacturer in any way.

 A 70-year-old man is referred to dermatology for evaluation of a scalp rash that has been present for months. Complaining bitterly of the itching in his scalp, he gives a history that includes treatment attempts with a number of medications, including prescription ketoconazole shampoo, oral antibiotics (eg, minocycline), and a course of oral terbinafine (250 mg/d for three weeks)—none of which has had a positive impact on the problem.

His wife, who is with him, at first denies and then finally admits to having an itchy scalp as well. Neither has a history of prior skin problems. 

The patient’s history is significant for type 2 diabetes and for well-controlled hypertension. He has been retired for many years and lives at home with his wife.

EXAMINATION
The patient appears disheveled, confused, and dirty. He is grossly oriented as to time and place, but hard of hearing and difficult to communicate with as a result.

His hair is greasy and dirty, as well as matted down in places. On closer inspection, scabs are noted in his scalp; they are widely distributed but especially heavy in the occipital and supra-auricular scalp. Many flakes of dandruff (some quite large) can also be seen.

Raising the thick hair over his nuchal scalp reveals a whitish sheen. Under 10x magnification, multiple tiny white papules are observed attached to each hair shaft, which accounts for the sheen. When examined under the microscope, the papules are clearly identified as nits. No adult lice are noted.

Significant tender adenopathy is elicited on palpation of the posterior neck area.

Continue reading for the discussion... 

DISCUSSION
Clearly, the basic problem is head lice (pediculosis capitis), with everything else stemming from it. This can be quite confusing for many reasons, not least of which is that one thinks of head lice as a pediatric problem.

The related issue is bacterial infection secondary to scratching and picking, usually from coagulase-negative staph. Minocycline or trimethoprim/sulfa would have been adequate for treatment but of course would not address the main problem: the lice. 

Ironically, one of the other impediments to a correct diagnosis was the severity of this patient’s case. It was, without a doubt, the worst I’ve seen in a 30-year career. The nits were so numerous as to render them almost impossible to see without magnification.

There’s little doubt that his wife had them too, adding to the potential for others (eg, grandchildren) around them to be infested as well. Furthermore, this represented a source for re-infestation despite treatment efforts.

Luckily, neither the organisms nor the nits remain viable for long off the body, which means they cannot reside and replicate on inanimate objects. Nonhumans cannot give or get human head lice. Given the organism’s need for warmth and aversion to light, there’s little chance for involvement in areas other than the scalp.

Both the patient and his wife were treated with oral and topical ivermectin. The topical form is applied once to a damp scalp, left on for 10 minutes, then rinsed out. It not only kills the adult organisms but also appears to render the nits nonviable—potentially obviating the necessity of using a nit comb.

The oral ivermectin (150 µg/kg ) was prescribed as follows: four 3-mg tablets now and another four tablets in 10 days to kill any remaining adults. Oral ivermectin is usually not necessary in the treatment of head lice and was only used in this case because of the severity.

Since their cases were so severe, I also advised them both to consider shaving their heads first to facilitate effective treatment. Again, this step is seldom necessary except in the most extreme cases. However, it also facilitated management of their secondary pyoderma, which was treated with trimethoprim/sulfa (double strength, bid for a week).

Since the itching caused by head lice is essentially an allergic reaction to the organism’s protein, that symptom may persist for some time, albeit with gradually diminishing intensity.

Continue reading for Joe Monroe's take-home learning points... 

TAKE-HOME LEARNING POINTS

• Pediculosis capitis (head lice) is seen mostly in children but affects adults as well.

• Pyoderma, secondary to scratching, can mislead the diagnostician and thereby delay diagnosis of the underlying problem.

• Oral trimethoprim/sulfa is often used to treat lice-associated pyoderma but does nothing directly to kill the lice themselves.

• The itching from head lice is a delayed hypersensitivity reaction to the lice protein and can take months after infestation to develop.

• Conversely, itching will develop early on in patients who have been sensitized by having had head lice in the past.

• The use of topical ivermectin has proven to be exceptionally effective in clinical trials.

DISCLOSURE: The author discloses having spoken and written about topical ivermectin at the behest of the manufacturer, but this article was not part of that process, nor is it supported by the product’s manufacturer in any way.